What ruins the game for you?

I ask this question out of interest since I recently saw a YouTuber say that to him the worst thing that could happen in this game while you play is to have an AFK even worse than to have a rager, which I found odd since to me it was the complete opposite, I don't mind someone being AFK, whether they have something to do, an emergency happened or they just don't want to play in the end, I know that with an AFK basically mean's the game is impossible to win but in all honestly I am ok with that since I can handle a loss in the end it's just a game no matter the rank (though in all honestly, I am talking more about normals I know people will think I am talking about rank) , yet when I have someone constantly say things like "Kill yourself" or "you must have downs" to me is what truly ruins the game since it's a complete disregard and belittlement to a person, an actual human being, and of course there is the classic "with a rager you can always mute but an AFK you are f*cked" saying but muting should not be the answer, it's just a game, not something that will be defining you for the rest of your existence and that one need's to give up all their moral's and empathy for but something to enjoy and have fun with, a game where you need to know that you are able to lose just as much as win it even if the fault ain't your own.

So I ask this