Riot has all sorts of teams except a psychologist one
I am truly serious when I say that, given how they handle player behavior. "Once toxic, always toxic unless you fall on your knees and buy our skins" is their motto.
Being toxic and flaming someone who deserves it? Not only will they be punished, but your account status will be degraded and therefore be more frequently matched with players like you. Creating two toxic players from one. The likelihood of this is extremely high, therefore reducing the healthy playerbase.
A much more preferable solution would be to independently match toxic players with healthy, anti-toxic players. Failure to comfort to their behavior should effectively and logically result in suspension. That's when a player proves how toxic they are.
From a personal example, I've noticed that being just as little toxic as saying a bad word in the chat will make you have all sorts of non-good players in the next game, for whatever reason in whichever team, but more likely in yours. No, Riot, I don't wanna see how it felt being flamed, I want to see how it feels to have a team that doesn't always impede my way to enjoying the game. Despite the gameplay itself being somewhat toxic, the least I wanted is toxic players too.
P.S. Nerf Irelia.