A lot of kids even up to 1500 end up dropping a pawn at some time vs. the opening. They just are not aware of the little tactics that come up. It catches many people by surprise.
Why are people annoyed by Scandinavian Defence?

Why are people annoyed by Scandinavian Defence?
No one says it's annoying, I really like playing against it, in fact.

I don't like it in non-incremental blitz because >95% of my opponents who play it rely on flagging as their main method of winning.
They usually blitz out aggressive moves to make white burn a lot of time, regardless of the quality of moves.

Nobody mentionned the real reason many are annoyed by scandinavian :
the important thing is that black (your opponent) chooses the structure he wants, and u cannot avoid it.
So black brings u on his/her field, and u have to be ready because scandinavian can be straightforward, especially if white plays carelessly.
Moreover, most don't like to "lose" their beloved e pawn, while pushing it (and protecting it unless u like to play 1.Nc3) is just wrong...
Correct!
A Scandinavian repertoire by IM John Bartholomew...
https://www.youtube.com/watch?v=8fEkJsfbQWM

I don't like it in non-incremental blitz because >95% of my opponents who play it rely on flagging as their main method of winning.
They usually blitz out aggressive moves to make white burn a lot of time, regardless of the quality of moves.
Which is why I won't play non-incremental blitz or pretty much anything.
Yeah I think it's about time I lay off the blitz a bit and play some slower time controls

I don't like it in non-incremental blitz because >95% of my opponents who play it rely on flagging as their main method of winning.
They usually blitz out aggressive moves to make white burn a lot of time, regardless of the quality of moves.
Which is why I won't play non-incremental blitz or pretty much anything.
Yeah I think it's about time I lay off the blitz a bit and play some slower time controls
https://www.chess.com/article/view/longer-time-controls-are-more-instructive

When I learned to play (in the 1980's) it was considered a beginner's mistake. When I came back to competitive play (around 2014) I was taken aback that it had become a valid opening. I still have trouble taking it seriously as a result.
Don't worry it has gone from a beginners mistake to a valid opening.
[i wrote a book on this opening]
But now i consider it a bad opening in both versions. [1. e4 d5 2. exd5 Qxd5 and 1. e4 d5 2. exd5 Nf6]

I think a competent correspondence player could almost refute the Center Counter in both variations. By this i mean that he could find many lines where Black has an opening disadvantage quite a bit worse than he usually gets.

From a psychological point of view white should respond with 2 d4 against the Scandinavian. White is taking back control of what the opening is called, quite annoying and worrisome to many Scandinavian players I'm fairly certain. I know I don't like seeing 2 d4. Sure, 2 d4 is inferior, but if Scandinavian players were focused on best opening moves they wouldn't be playing the Scandinavian.

I enjoy playing against it. It allows me to develop my pieces while black can’t (because i’m constantly attack their queen).

My performance rating with 2...Qxd5 3 Nc3 Qd8 is 45 rating points higher than with 3...Qd6, and 56 points higher with 3...Qd8 than with 2...Nf6. My style is best suited for the relatively simpler more solid 3...Qd8. My guess is aggressive players score better with Smerdon's Scandinavian repertoire based on 2...Nf6.
There is a common piece placement on AMATEUR LEVEL. You just don't get it. Like in the london system you can play a lot of the moves in the scandinavian on auto-pilot even if they aren't good for example retreating the queen to c7 no matter what. I'm not talking about master level chess. A really strong player will of course better moves. To you the moves of amateurs seem stupid but this is how the scandinavian or the london system is played on low level chess.