Why does Riot ban like this?

I understand toxicity is a huge problem but the way Riot hands out bans to people is ridiculous. Riot likes banning people for calling their teammates bad more than banning people who actually ruin the gameplay immediately. You implemented a mute button for people that get annoyed, but no button for people who are trolling teammates like a kick button or something like that. I understand toxicity is a problem but is it really fair to ban people more often for flaming teammates or calling them bad than intentionally feeding? I find that if i wanted to ruin a game by intentionally feeding, afking or trolling, I would most likely not be punished, yet if I called my teammates trash or simply said "fuck you" I would get a chat restriction, 2 week ban or even a perma ban. Riot needs to do something else with handling toxicity because banning people who calls their teammate a troll when they are taking all the junglers farm is unfair and I think it needs to be addressed.

edit:I think encouraging self harm and racism is different than flaming and should be handled differently.

(sorry if it sounds a bit weird I had it done really well then I tried to copy and paste it and it broke)