Was watching Guardsman Bob last night and he was having a talk about how he thinks players who get banned for mis-using the chat (Raging at team mates, calling them noobs, etc.) shouldn't get banned from the game but should be instead banned from using the chat in game. He also explained the counter-argument of how this could cause problems involving team communication, but it wouldn't be any better if he was un-muted because the player in question wasn't using his chat constructively anyway.
Also, this way instead of getting banned and just raging on their smurfs, they'll want to play on their mains because that's where their skins/champs are so they'll put up with the mute