Why exactly does the London get so much hate?

The same thing I could say about players who only play Kings Gambit or Sicilian Dragon.

It's actually London players who are often complacent. "There's no way I could play main lines and enter a King's Indian or Nimzo-Indian. There's way too much theory!" "If I play e4 then opponent will play Sicilian and omg that's way too sharp and theoretical!" Playing the London doesn't make you a wimp but this attitude does.

Some of them even believe that those openings aren't even good because they are imbued with such irrational fear of the Sicilian Najdorf or something like that. They are taught to be afraid. They are taught to stay in the shallow end.

If they would break out of their shell and actually learn something more about the game, it would benefit ALL of us. "There's no way I could play the Sicilian, it's way too sharp for me! There's too much theory! Sicilian Najdorf is trash!" Do you even know what that means? Have you ever even tried to play a Sicilian or is that just what you were told?

But those openings aren't systems and you have to respond to the opponent and play aggressively.

Toth is correct! For a beginner to repeatedly play the same "system," usually paying very little attention to their opponent's reply, is no way to become a better player.  Even for a more experienced player, sticking to one--and only one--system is cheating yourself out of all the riches chess has to offer. 

On the other hand, players like Gata Kamsky have produced a lot of masterpieces using the London

Even then, the Yugoslav Attack is a fun opening and both players attack each other and challenge each other in the opening. King's Gambit is very sharp and has a lot of variation. I don't play King's Gambit though as it's inferior to the Nf3 lines.

For your information King's indian is initiated by Black and can be played against the London. I was going to suggest you could try it in order to relieve the pain and pump that elo rating a bit but all of a sudden this hilarious message from you appeared in my screen.
Stepping outside an opening you don't like from your opponent remains your responsibility. If you play OTB or plan to do it someday you should actually develop some counter move against what apparently bother you a lot. I had to do it in the past against stuff I hated. This is also what chess is about.

esp the Dragon, which means the majority of games with Black will be a Yugoslav attack, which is mostly about playing against the opponent's preparation instead of the actual opponent.

When I say King's Indian, I mean an actual King's Indian line for white. Of course I know the "King's Indian structure" can be played against the London, but it's not a true King's Indian. White is not playing a King's Indian they are playing a London.

This is a true King's Indian from the white perspective:

And then it deviates.

Whatever the reason that makes you believe that your opponent owes you to pick a sharp line, truth is they simply don't.

Only for GMs who revised loads of theory. Not for the rest of us.

You don't what the hell you're talking about. I never said the opponent owes me a sharp line. You haven't read any of my points. I always said of course you have to respond and adapt to anything your opponent plays at the board without being complacent. You just made strawman arguments without acknowledging anything that I've already said so watch what you say.

Anything I've said is based on the point of why I don't like the London for white, and what is wrong with depending on a system opening.

I played London for maybe a year some time ago, with some success. Reverted to Scotch as I prefer open games. This seems to serve me better with less clutter in the centre. 

I don't think openings make much difference at my weak level as pretty much every game depends on who blunders first, or worst.

Play 1.e4 or after 1.d4, 2.c4 and you will never suffer again because of this awful opening FOR WHITE, I absolutely guarantee it.

Not true, in the Dragon I've seen (below GM) games reliant on theory knowledge, I've also seen folks securing draws vs much higher rated players purely on theoretical preparation or even scoring points exclusively due to theory preparation. All this not at GM level but above 2000 ( fide, not chess.com ). The rating gap of course was reflected in the results, after the White player started using the English.

Exactly. If you switch to d4-c4 or e4 then you will learn a lot more about the game rather than just depending on a system opening.

you're the one making strawman arguments when you compare the London to the Englund, comparing a sound to an unsound opening.

Also, I don't need advice on what to say, thank you very much.

People don't need to play any of the lines you've quoted so far even at a high/titled range, it's as simple as that.

You are only talking about a specific scenario in tournaments. Not for the average person.

Also if you are talking about theoretical preparation in tournaments, then the same applies to literally any other opening. Like someone can prepare a long line in the London or Rossolimo. Preparation is not exclusive to the Dragon.

You can't seriously suggest that all people ever do is prepare for the Dragon because it's "theoretical" and then when it comes to other openings they just say "time to play without theory as it isn't a Sicilian". It's the same with literally every other opening.

I didn't compare the London to the Englund. I was talking about reasons why someone would dislike an opening. It's not a strawman argument.

A strawman argument is where you make up an argument just to knock it down and then act like it was the other person who said it. This is exactly what you did as you suggested that "I expect the opponent to play a sharp line" which is completely contrary to what I said before.

You are putting words in my mouth or, in other words, making a strawman argument.

You actually do keep quoting every sharp line you've heard of, which can't be from experience because only Kasparov has experience all of them together and say people should play these.

They can actually play whatever they want, if they want to go for a quiet equal position in the opening they'll go for that, it's perfectly ok strategy, It's completely fine if someone wants to opt for something quieter and not the bayonet attack vs the KID. They'll maneuver and then there's a whole middlegame and endgame ahead.