Focus On Your Game, Not Your Chat Box
Seriously, I'm tired of playing games with little cry babies who think they are better than every other player in the entire world.
Stop wasting your time talking in chat.
No one cares who is bad and who isn't bad. No one cares who isn't doing anything in fights. No one cares who is useless on your team.
No one cares how much you hate your ADC. No one cares how much you hate your Support. No one cares how much you hate your Top Lane. No one cares how much you hate your Jungler.
Stop pressing Enter. You have Pings, if you have something important that needs communicated you don't need to be typing.
You can't use abilities while you are typing. You probably aren't moving while you are typing. You probably aren't CS'ing because you are typing. You probably aren't focused on the game, because you are typing.
STOP. JUST S-T-O-P.
No one minds having a good time with their teammates joking around, but when you are tilting yourself and everyone else on your team, it's time you realize that you are causing problems and it needs to end.
Watch your mini map. Focus on your cool downs. Keep good positioning. Remember to put wards down. Think carefully about what objective should be prioritized. Forget about your teammates. Set an example.
Control your rage. Throw away your hatred. Win your game.
You don't need to mute anyone. Forget that Enter even exists. There's no chat box.
Smite on CD? PING. Enemy Flashed? PING. Enemy dead? PING. Need to back for an item? PING.
It's your game to win, or yours to lose. Stop blaming your team. Stop flaming your team.
Take control and accept your responsibility to do your best.