People don't like getting bursted.
I don't think anyone really has any issue with any of the classes in the game.
It just that when the champion they face is going to kill them in 2 seconds or less it turns what could be a fun and interesting game into a game where every single mistake can be a huge problem.
So why does riot keep making everything so bursty.
Heck mand I think a good deal of the toxicity in the game stems from this. Your team mate makes what could be considered a minor mistake, but because he is up against something that can kill him in a second and his play directly affects you, you get mad at him and verbally tell that person off.