Yeah, it doesn't! It is usually just aggravation that's piled onto a game that's likely going poorly already. It's frustrating as hell!
And like you could have this guy keep on and on and on at you about how ugly and awful your build is because you didn't build Morellonomicon even though the MR of Grail would be better, you're awful because you "have to" build Morello's every time because I guess that's what MOBAfire said.
You could defend yourself, you can type back, you can point out how he shouldn't be writing anything when he can't even figure out how to use Tides of Blood. But there's a line we can't cross. Neither you nor I are permitted to, for example, call him a retard who can't even figure out how items work, no matter how true that may or may not be.
There is a saying that goes "Don't argue with idiots, drunks, or children" because if you argue with their stupid, they won't change, they'll just throw more stupid at you.
And like you said those guys are children. Idiot children. We aren't going to get anything from typing at them, so we'll just ignore it or mute them if we are tilted and can't ignore it, because there is only one thing that can happen if someone does fire back.
So just stay out of Ranked, bind "glhf" and "gg" to hotkeys, take out your Enter key, and mute anyone who even starts to show signs of acting up. Because they aren't worth it.
Hope you have some better games. Good luck and just take care of yourself.