A strategy can be legit and low skill at the same time
And what
@Barrogh said is 100% legit for FG's in particular. Yes there is often a lot of strategies that seem impossible to beat to begin with, and there is counterplay to most of them (Otherwise they're basically OP and need nerfs), but it doesn't change the fact that at the time people will get salty about it, regardless of the availability of counterplay.
Literally everyone is guilty of it. If you say you aren't then you're either lying, you're playing a ridiculous character, or you're infinitely better than the rest of us and should probably sign up at the next major.
I don't have fun whenever I get my Bane counterpicked by Fate. Yes, I know there is multiple methods of counterplay available, and I know them all, but it doesn't change the fact that sometimes I'm just having a shite day, or I'm on a losing streak, or whatever.
Basically what I'm getting at is that FG's are hard to pick up for new players. When I first picked up IJ2 I thought Darkseid was ridiculous. Knockdown zoning, 50/50's when he leaves the ground, easily 45%+ combo damage for a bar, oki setups, mobility, all the works. I got past it, but that's because I knew the mechanics of the game and adapted them to my own situation.
A new player isn't going to know these mechanics, and they're just gonna get salty and give up. They won't bother to learn the mechanics because what's the point? Hell, I was playing a KotH with my real life friends (Who are by no means FG players) and I picked Robin. I wrecked face with them and they didn't know what to do. They gave up, as most people would. You can't just LEARN stuff like that over time, you need to dedicate time in the lab to be able to learn frames and what counters your specific character(s) have.
In most other games you CAN learn stuff like that. Like in R6 I remember I would always get spawn peaked from the same spots every game and it got me salty. I thought it was broken. Then I kept playing along and I figured it out eventually. No ridiculous game mechanics or testing required, just a little bit of common sense, patience, and a good aim.
Tldr; Yes, stuff like this exists in every game basically, but fighting games punish new/unprepared players SIGNIFICANTLY harder than most other games people play. The only other genre I can think of that punishes players as hard is MOBA's (Also a really salty community) and games like Starcraft (Also a pretty salty community)
Seeing a trend?