PSA: I'd rather play with a good toxic player in Ranked, than a polite bad player.
I think that the casual players are spamming the boards too much with their "lets all be friends" nonsense and crusade against "toxicity", funny how they act toxic towards anyone they consider toxic.
League of Legends ranked solo que is a competitive environment, the number 1 objective is winning. I don't care if I am playing with a racist, with a mass murderer, with an alien or with a psychopath. I don't care if you are male or female, I don't care if you are nice or rude, I don't care if you are polite or toxic, you can insult me all you want, I will just mute you like any sane and intelligent person would. THE ONLY THING THAT I CARE ABOUT AND THE ONLY THING THAT MATTERS, IS HOW GOOD YOU ARE AT PLAYING THE GAME.
Winning is the objective, I am not here to be your friend, I am not here to help you improve, I am here to win. If you play good, if you are carry the game or help with carrying, then you are a GOOD and VALUABLE team mate.
Casuals and Lyte are clueless, stop trying to enforce your idiotic morality on others. Go enforce it in normal games or fun game modes, but keep it out of my high elo ranked games.

on the enemy team, it's also when you have to work with (or against) a Toxic Teammate.