Why I quit - Toxicity

As of today I've quit league of legends, I understand I'm only one of millions and nobody cares, but I feel that Riot should know why this happens.

My experience in the last few months of league has been depressing 9/10 games there's in-fighting in the team, an afk, a troll ect. but what really sets me off is that this behavior is "accepted". I queued up for a ranked game today and had my support go afk mid game, honestly I wasn't surprised as nearly every game i play in ranked has an afk. But that's not even the worst part, the entire game I had to deal with my midlaner, toplaner and jungler verbally harassing me in the chat calling me shit, telling me i'm feeding (I ended up going like 7/9 without a support "feeding") I didn't mute them, I want to understand what motivates them to do this. I reported them after the game (as I find myself doing too often...) And this game is just one of many I've had in this scenario. Alas I feel as if i'll be the one punished, for trying to be nice to my teammates, and not being an absolute dick. It's almost like if you do flame your team, your a dick, and if you don't, your a "sensitive fucktard" as most riven mains would put it. I don't know how the report system works, but if they can report me for "Being a %%%got" and I can get punished, Then i don't see a point in having the system in the first place. I doubt this post will attract anything but trolls as most posts about the toxicity in the community tend to go that route...