Isn't ruining others' games a form of toxicity in itself?

So I just got a 14 day ban for hate speech, and as my first offence I completely understand why I was punished. I made some nasty jokes about our Ezreal in bad taste after he afk'd for the first 2 mins then refused to communicate.

What pisses me off though is that this Ezreal can continue to play and ruin others' experiences after denying his support gold and basically telling him to leave him alone? He went splitpushing and refused to help the team and even inted a couple of kills on purpose, saying that he wouldn't help the team unless his critics (braum and I) said "sry". No one in my game besides the Ezreal (who presumably reported me) really had any issue with my jokes. Everyone took issue with his attitude, including top, mid and support.

There is something you can do to battle toxicity - mute. But there's nothing you can do to deal with these kinds of players that ruin other people's games. Furthermore, these players, it seems, rarely get punished for their behaviour. Not only do I think this behaviour is toxic in itself, I also think that it encourages verbal toxicity.

I'm not asking for pity, or for an unban. I know why I was banned, and I take responsibility for my actions. I just want Riot to make these people take responsibility for theirs, too.