Nice post, Mike!
Why your openings fail.

One thing the OP failed to factor in are Opponent factors.
What are the typical ideas for the opponent?
Why are other moves for my opponent bad?
What is my opponent trying to achieve, both in the main lines and the wrong lines. Even when wrong, you still must understand what he is looking to do.
For example, take the French Advance. It is not good enough just to know what you need to do and why. For example, if you are playing Black, after 1.e4 e6 2.d4 d5 3.e5 c5 4.c3 Nc6:
A) Why is 5.f4 bad?
B) Why is 5.Nf3 Qb6 6.a3 played? Why not shouldn't White just castle ASAP?
C) What move by Black, if played too early, will allow rapid castling at no cost to White?
It ain't enough only knowing Black's ideas and Black's problem, even if you are only playing the opening from the Black side, like if you play 1.c4 as White.

One thing the OP failed to factor in are Opponent factors.
What are the typical ideas for the opponent?
Why are other moves for my opponent bad?
What is my opponent trying to achieve, both in the main lines and the wrong lines. Even when wrong, you still must understand what he is looking to do.
For example, take the French Advance. It is not good enough just to know what you need to do and why. For example, if you are playing Black, after 1.e4 e6 2.d4 d5 3.e5 c5 4.c3 Nc6:
A) Why is 5.f4 bad?
B) Why is 5.Nf3 Qb6 6.a3 played? Why not shouldn't White just castle ASAP?
C) What move by Black, if played too early, will allow rapid castling at no cost to White?
It ain't enough only knowing Black's ideas and Black's problem, even if you are only playing the opening from the Black side, like if you play 1.c4 as White.
This is meant as a K.I.S.S list.

One thing the OP failed to factor in are Opponent factors.
What are the typical ideas for the opponent?
Why are other moves for my opponent bad?
What is my opponent trying to achieve, both in the main lines and the wrong lines. Even when wrong, you still must understand what he is looking to do.
For example, take the French Advance. It is not good enough just to know what you need to do and why. For example, if you are playing Black, after 1.e4 e6 2.d4 d5 3.e5 c5 4.c3 Nc6:
A) Why is 5.f4 bad?
B) Why is 5.Nf3 Qb6 6.a3 played? Why not shouldn't White just castle ASAP?
C) What move by Black, if played too early, will allow rapid castling at no cost to White?
It ain't enough only knowing Black's ideas and Black's problem, even if you are only playing the opening from the Black side, like if you play 1.c4 as White.
That's actually a very good supplement to this post. Thanks ThrillerFan.

One thing the OP failed to factor in are Opponent factors.
What are the typical ideas for the opponent?
Why are other moves for my opponent bad?
What is my opponent trying to achieve, both in the main lines and the wrong lines. Even when wrong, you still must understand what he is looking to do.
For example, take the French Advance. It is not good enough just to know what you need to do and why. For example, if you are playing Black, after 1.e4 e6 2.d4 d5 3.e5 c5 4.c3 Nc6:
A) Why is 5.f4 bad?
B) Why is 5.Nf3 Qb6 6.a3 played? Why not shouldn't White just castle ASAP?
C) What move by Black, if played too early, will allow rapid castling at no cost to White?
It ain't enough only knowing Black's ideas and Black's problem, even if you are only playing the opening from the Black side, like if you play 1.c4 as White.
So, all the bad moves need to be investigated also. Hmm, but GMs don't usually play or talk about the ugliest of things or every possible move. Sure seems like a lot to need to understand just to play a game. What's this patzer across from me trying to do now? Hmm, let me count the ways...oh boy, this is getting super complicated and quick. This isn't very fun.

I hear quite a bit on how openings don’t really matter at the beginner and intermediate levels but I like to say certain openings not only achieve a positional or imbalance or preferable game (which makes the game enjoyable), but moreover, can be a transposition weapon to avoid an opponents pet line.
As white, I prefer to steer the game in familiar territory. As black, I like imbalance and counter attacking. Certain openings fit this bill beyond replying with 1.e4, e5 and 2. d4, d5 even though this is highly recommended.
My personal experience and still working thru this is my opening reportorial is not the reason that I lose, it’s because my tactics and middle game is going thru improvement.
Therefore I blame my losses on me and not on my opening choices.

One thing the OP failed to factor in are Opponent factors.
What are the typical ideas for the opponent?
Why are other moves for my opponent bad?
What is my opponent trying to achieve, both in the main lines and the wrong lines. Even when wrong, you still must understand what he is looking to do.
For example, take the French Advance. It is not good enough just to know what you need to do and why. For example, if you are playing Black, after 1.e4 e6 2.d4 d5 3.e5 c5 4.c3 Nc6:
A) Why is 5.f4 bad?
B) Why is 5.Nf3 Qb6 6.a3 played? Why not shouldn't White just castle ASAP?
C) What move by Black, if played too early, will allow rapid castling at no cost to White?
It ain't enough only knowing Black's ideas and Black's problem, even if you are only playing the opening from the Black side, like if you play 1.c4 as White.
This is meant as a K.I.S.S list.
Problem is, you cannot half-a$$ it and expect to succeed. You must understand BOTH sides. You have to understand White's objectives when you are Black and Black's objectives when you are White.
Trying to make the KISS argument is like teaching a hitter how to run the bases without teaching him how to read a fast ball or curve ball or understanding the opposing pitcher's strengths and weaknesses!

One thing the OP failed to factor in are Opponent factors.
What are the typical ideas for the opponent?
Why are other moves for my opponent bad?
What is my opponent trying to achieve, both in the main lines and the wrong lines. Even when wrong, you still must understand what he is looking to do.
For example, take the French Advance. It is not good enough just to know what you need to do and why. For example, if you are playing Black, after 1.e4 e6 2.d4 d5 3.e5 c5 4.c3 Nc6:
A) Why is 5.f4 bad?
B) Why is 5.Nf3 Qb6 6.a3 played? Why not shouldn't White just castle ASAP?
C) What move by Black, if played too early, will allow rapid castling at no cost to White?
It ain't enough only knowing Black's ideas and Black's problem, even if you are only playing the opening from the Black side, like if you play 1.c4 as White.
So, all the bad moves need to be investigated also. Hmm, but GMs don't usually play or talk about the ugliest of things or every possible move. Sure seems like a lot to need to understand just to play a game. What's this patzer across from me trying to do now? Hmm, let me count the ways...oh boy, this is getting super complicated and quick. This isn't very fun.
They do not study every bad move. They understand fully the reason for the best move, and usually based on that, will figure out why other moves are bad.
For example, in the advance French, White is looking to blockade the center with d4 and e5, maybe not via pawns, but via occupancy of the 2 squares by pieces. Well, if f2-f4 is pushed, the DSB on c1 is bad and the g1-a7 diagonal is severely weakened, and the d4-pawn may not cover e5 due to a pin to the king, and there may be tactics on d4 that land the White Queen there and then an absolute pin to the King. It also wastes time in White's development.
If Black does not understand these ideas, White will simply get away with the bad move, and now have an advanced center with a safe king (moved to h1 and Black did nothing to counter White's wasted time) and White is a lot better!

One thing the OP failed to factor in are Opponent factors.
What are the typical ideas for the opponent?
Why are other moves for my opponent bad?
What is my opponent trying to achieve, both in the main lines and the wrong lines. Even when wrong, you still must understand what he is looking to do.
For example, take the French Advance. It is not good enough just to know what you need to do and why. For example, if you are playing Black, after 1.e4 e6 2.d4 d5 3.e5 c5 4.c3 Nc6:
A) Why is 5.f4 bad?
B) Why is 5.Nf3 Qb6 6.a3 played? Why not shouldn't White just castle ASAP?
C) What move by Black, if played too early, will allow rapid castling at no cost to White?
It ain't enough only knowing Black's ideas and Black's problem, even if you are only playing the opening from the Black side, like if you play 1.c4 as White.
So, all the bad moves need to be investigated also. Hmm, but GMs don't usually play or talk about the ugliest of things or every possible move. Sure seems like a lot to need to understand just to play a game. What's this patzer across from me trying to do now? Hmm, let me count the ways...oh boy, this is getting super complicated and quick. This isn't very fun.
They do not study every bad move. They understand fully the reason for the best move, and usually based on that, will figure out why other moves are bad.
For example, in the advance French, White is looking to blockade the center with d4 and e5, maybe not via pawns, but via occupancy of the 2 squares by pieces. Well, if f2-f4 is pushed, the DSB on c1 is bad and the g1-a7 diagonal is severely weakened, and the d4-pawn may not cover e5 due to a pin to the king, and there may be tactics on d4 that land the White Queen there and then an absolute pin to the King. It also wastes time in White's development.
If Black does not understand these ideas, White will simply get away with the bad move, and now have an advanced center with a safe king (moved to h1 and Black did nothing to counter White's wasted time) and White is a lot better!
A kid learning to play tee ball doesn't need to know how to read a pitch.

One thing the OP failed to factor in are Opponent factors.
What are the typical ideas for the opponent?
Why are other moves for my opponent bad?
What is my opponent trying to achieve, both in the main lines and the wrong lines. Even when wrong, you still must understand what he is looking to do.
For example, take the French Advance. It is not good enough just to know what you need to do and why. For example, if you are playing Black, after 1.e4 e6 2.d4 d5 3.e5 c5 4.c3 Nc6:
A) Why is 5.f4 bad?
B) Why is 5.Nf3 Qb6 6.a3 played? Why not shouldn't White just castle ASAP?
C) What move by Black, if played too early, will allow rapid castling at no cost to White?
It ain't enough only knowing Black's ideas and Black's problem, even if you are only playing the opening from the Black side, like if you play 1.c4 as White.
So, all the bad moves need to be investigated also. Hmm, but GMs don't usually play or talk about the ugliest of things or every possible move. Sure seems like a lot to need to understand just to play a game. What's this patzer across from me trying to do now? Hmm, let me count the ways...oh boy, this is getting super complicated and quick. This isn't very fun.
They do not study every bad move. They understand fully the reason for the best move, and usually based on that, will figure out why other moves are bad.
For example, in the advance French, White is looking to blockade the center with d4 and e5, maybe not via pawns, but via occupancy of the 2 squares by pieces. Well, if f2-f4 is pushed, the DSB on c1 is bad and the g1-a7 diagonal is severely weakened, and the d4-pawn may not cover e5 due to a pin to the king, and there may be tactics on d4 that land the White Queen there and then an absolute pin to the King. It also wastes time in White's development.
If Black does not understand these ideas, White will simply get away with the bad move, and now have an advanced center with a safe king (moved to h1 and Black did nothing to counter White's wasted time) and White is a lot better!
A kid learning to play tee ball doesn't need to know how to read a pitch.
You missed the point completely! We are not talking T-Ball you moron! I was talking baseball in that analogy!
The whole point is you cannot learn how to do anything only knowing half the basics. Knowing the French vs knowing the Sicilian is where choice comes into play, like choosing whether you want pancakes or waffles or French Toast, but what good is it knowing how to operate a frying pan or waffle iron if you do not know how to make the batter? And if you come back with some dumba$$ response like heat frozen ones in the microwave or toaster, you are the dumbest living thing on the planet!

One thing the OP failed to factor in are Opponent factors.
What are the typical ideas for the opponent?
Why are other moves for my opponent bad?
What is my opponent trying to achieve, both in the main lines and the wrong lines. Even when wrong, you still must understand what he is looking to do.
For example, take the French Advance. It is not good enough just to know what you need to do and why. For example, if you are playing Black, after 1.e4 e6 2.d4 d5 3.e5 c5 4.c3 Nc6:
A) Why is 5.f4 bad?
B) Why is 5.Nf3 Qb6 6.a3 played? Why not shouldn't White just castle ASAP?
C) What move by Black, if played too early, will allow rapid castling at no cost to White?
It ain't enough only knowing Black's ideas and Black's problem, even if you are only playing the opening from the Black side, like if you play 1.c4 as White.
So, all the bad moves need to be investigated also. Hmm, but GMs don't usually play or talk about the ugliest of things or every possible move. Sure seems like a lot to need to understand just to play a game. What's this patzer across from me trying to do now? Hmm, let me count the ways...oh boy, this is getting super complicated and quick. This isn't very fun.
They do not study every bad move. They understand fully the reason for the best move, and usually based on that, will figure out why other moves are bad.
For example, in the advance French, White is looking to blockade the center with d4 and e5, maybe not via pawns, but via occupancy of the 2 squares by pieces. Well, if f2-f4 is pushed, the DSB on c1 is bad and the g1-a7 diagonal is severely weakened, and the d4-pawn may not cover e5 due to a pin to the king, and there may be tactics on d4 that land the White Queen there and then an absolute pin to the King. It also wastes time in White's development.
If Black does not understand these ideas, White will simply get away with the bad move, and now have an advanced center with a safe king (moved to h1 and Black did nothing to counter White's wasted time) and White is a lot better!
A kid learning to play tee ball doesn't need to know how to read a pitch.
You missed the point completely! We are not talking T-Ball you moron! I was talking baseball in that analogy!
The whole point is you cannot learn how to do anything only knowing half the basics. Knowing the French vs knowing the Sicilian is where choice comes into play, like choosing whether you want pancakes or waffles or French Toast, but what good is it knowing how to operate a frying pan or waffle iron if you do not know how to make the batter? And if you come back with some dumba$$ response like heat frozen ones in the microwave or toaster, you are the dumbest living thing on the planet!
Ok Yankee Doodle Burnt Waffle Brainfarts
You missed the point. You made the baseball analogy and I gave it similar context (the intended audience). It isn't the semi-pro player.
Your last move example was a good one to support identifying a good move vs a bad one. But when a (any) bad move is played, you can't expect someone with little experience to "know it all". You didn't know it all before you started playing. You didn't understand everything under the sun about the French Defence, the King's Indian Defence, and every possible opening by White.
You came out attacking the OP by saying he "failed" this and that. I'm not interested in ruining his thread with arguments.
So, let go my Eggo and try to be a little more respectful and empathetic.
Why your openings fail.
Before you blame your losses on your choice of opening, you should first understand 2 of the main reasons why your opening could fail:
Here’s the important details:
The opening is just the start of the game. The purpose is to develop your pieces and achieve a decent middle-game position. Accept that you cannot always get an advantage from the opening – and if you do – that’s a bonus.
A typical example to further illustrate the point
Picture this. A chess player achieves a good middle-game position against a stronger player. However, since his opponent is a stronger player, over the course of the game his position gets worse. He eventually loses and isn’t even sure why he lost. Should he blame the opening for his loss? Of course not.
You cannot expect your choice of opening to compensate for a lack in other important middle- or endgame skills
More often than not, in games below master level, it’s not your choice of opening that fails you. Rather, it’s your (lack of) knowledge and understanding of how that opening should be played that fails you.
Which brings us to the 2nd reason why your opening may fail you:
Memorizing the main variations of the opening you play can be useful – as long as your opponent plays the moves you know or expect. But what happens when they deviate from the moves you memorized?
The moment an opening deviate from the main lines, your true understanding of the opening will be tested.
Magnus Carlsen often makes effective use of such opening deviations. He avoids his opponent’s opening preparation by occasionally choosing a move that – even if it may theoretically be an inferior move – neutralizes his opponent’s opening preparation. He does this because he believes his strength lies in his understanding of the game. Naturally he wants to play to his strengths, so he is willing to make a small compromise if that will steer the game into a direction where his strengths come into play.
How well do you understand your opening?
You can test your understanding of your opening by checking how well you can answer the questions below:
That said, what can you do to improve your understanding the opening you choose to play?
If you couldn’t answer the above questions as well as you would like to, I recommend you check out a openings database and select a number of games (say 20-50 games), where your choice of opening was played by masters. Go through these games and keep the above questions in mind. You will soon start to notice the typical patterns in that opening. By studying a whole number of games in this way (and whilst referring to the list of questions above) you will get a much better understanding of the opening.
Tip: When you’re looking for an opening to learn – go for main-line openings. There is a good reason why they are called “main-line”. They are time-tested and over the course of your chess development, you will be glad you studied them. “Sideline-openings” have their place and require much less study but if you are serious about improving your chess–sideline openings will not give you a solid enough foundation.