Back when I played e4, at least, I was annoyed because it violated the “don’t move your queen” principle and it wasn’t so easy to punish.
Why are people annoyed by Scandinavian Defence?
Why would you get "annoyed" by any chess opening? It's a chess game! There are many good ways for both sides to get their pieces out, and it makes no sense to have an emotional reaction because your opponent chooses one way instead of another. There are going to be positional decisions to make and tactics to calculate in every game

At the lower levels, particularly around my level and lower is likley because once both players have finished their development, there's just nothing in the middle game. In most other openings, you get nice potential for pawn breaks in the centre and other attacking ideas which will bring us to the endgame if nobody blundered checkmate (Or checkmate was blundered but not seen), but the Scandinavian kills all of this out the gates with an early pawn trade in the centre and the middle game will be about making small improving moves (Which might be fine at the intermediate or advanced levels, but us beginners will struggle to find those quiet improving moves).
And yes, I am aware that there are more aggressive lines such as this

openings that blatantly violate certain opening principles, be it the scandinavian, or the orangutan opening or the bird variation of the ruy lopez or the mikenas, montevideo retreat, tend to elicit a big gut reaction in a certain number of the chess populace.
This attitude is often an advantage to those playing it, who know the opening/defense is better than it looks and and their opponent is bound to play with premature aggression or even cavalier dismissal.
Sometimes, even knowing an opening is ok is not sufficient to escape that psychological state. While i respect the Scandinavian as a defense if anyone would play the qd8 variation, i would have a hard time not feeling a strong itch to try and punish it, despite knowing its ok

The Scandi is quite solid. Tbh, I have to thank the op for reminding me about this opening (for some reason I'd forgotten that it even existed!) You mostly get a better version of the Caro-Kann (as GM Larsen once rightly remarked). The reason it's not too popular has to do with chess fashion at the moment rather that it's objective strength.
I'll most definitely use it and post my results here!

Here, finally. This one's against @Naroditsky-Bot (2650). I really wanted to play it live, but for some reason none of the sonnuva-guns want to play 1.e4 with me today! Anyway, here's the game:
https://www.chess.com/game/computer/8877007
I could go on with "so you see, the Scandinavian's not that bad"... but I just did so passive-aggressively by saying "I could go on with..." . Lol okay, that's just me being stupid. Ignore that. And yeah, btw, I really do think Scandi is really good (maybe even underrated).

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.
There was a time when I thought so too but when I found out IM Michael Melts played it regularly on ICCF and published a book on the Qd6 line, I realized I had to give more thought on my opinion. I think even if the scandi turnss out to be unsound, it is still something you have to take seriously. BTW Melt's IM title is in correspondence chess....just thought I should mention that to avoid confusion.

Back when I played e4, at least, I was annoyed because it violated the “don’t move your queen” principle and it wasn’t so easy to punish.
yeah exactly, white feels winning but doesnt know where to go from there

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.
There was a time when I thought so too but when I found out IM Michael Melts played it regularly on ICCF and published a book on the Qd6 line, I realized I had to give more thought on my opinion. I think even if the scandi turnss out to be unsound, it is still something you have to take seriously. BTW Melt's IM title is in correspondence chess....just thought I should mention that to avoid confusion.
Melts got the ICCF IM title back in 1994, and stopped playing there 23 years ago. Which is the pre-engine era, and the games had plenty of mistakes.
And his book is useful only for archival purposes. Structurally, it is a horrible mess, and with a ton of analytical mistakes.
Current experience says that the 3...Qd6 line has some problems which are not easy to solve, while in the 3...Qa5 variation white is objectively better like that:
In a modern ICCF game, white is playing for two results in this position.
In OTB games, this is quite double-edged because white is "almost" overextended on the kingside, and this gives Black plenty of counterchances. While I do not doubt that white is better here, I would pick another, more practical solution to prove something.

From what I've heard, the Scandinavian isn't the best opening. But it looks fun, so I'll give it a try!

Melts got the ICCF IM title back in 1994, and stopped playing there 23 years ago. Which is the pre-engine era, and the games had plenty of mistakes.
And his book is useful only for archival purposes. Structurally, it is a horrible mess, and with a ton of analytical mistakes.
Current experience says that the 3...Qd6 line has some problems which are not easy to solve, while in the 3...Qa5 variation white is objectively better like that:
In a modern ICCF game, white is playing for two results in this position.
In OTB games, this is quite double-edged because white is "almost" overextended on the kingside, and this gives Black plenty of counterchances. While I do not doubt that white is better here, I would pick another, more practical solution to prove something.
Thanks for that. I didnt realize that about Melts. Also those kinds of positions with the bishops may be why the scandi is popular at below master level. At master level the bishop pair can seem like a totally winning advantage in the hands of a player with great endgame technique but it is rare to find a player with such skill at class level. What I am saying i that even if in the above position white manages to neutralize blacks counter play and get a simpler version of the bishop pair advantage, he may or may not know how to win it.

jamesstack wrote: Thanks for that. I didnt realize that about Melts. Also those kinds of positions with the bishops may be why the scandi is popular at below master level. At master level the bishop pair can seem like a totally winning advantage in the hands of a player with great endgame technique but it is rare to find a player with such skill at class level. What I am saying i that even if in the above position white manages to neutralize blacks counter play and get a simpler version of the bishop pair advantage, he may or may not know how to win it.
Similar can said about the Tarrasch Defense in that the IQP is not easy to exploit at club level. The Scandinavian and Tarrasch Defense are what I play. In the Scandinavian I use both 3...Qd8 and 3...Qa5.
"Why are people annoyed by Scandinavian Defence?"
Theoretically, it loses.
Please cite the TCEC event where this shocking new refutation was discovered. Here's a list of openings used by the way. Good luck hunting!
https://www.chessprogramming.org/TCEC_Season_19
Where is that "shocking new refutation"?
There were two Scandi games played there, and Black got miserable positions in both of them.