The cause of League's reputation for having a toxic community.
It is pretty well known that the community for this game has a reputation for being "toxic" (thanks Riot for coining that overused term), a reputation worse than pretty much any other online game currently. While being popular is always going to enhance negative reputations, I've never seen it so prevalent as with this game.
And after playing for quite a while, I've figured out why. I've figured out what it is that causes this. And it's actually very simple: The Report system itself IS the cause.
Obviously, the immediate reaction is "That's crazy, how does a system that punishes "toxic" players and so forth make the community more toxic? That's stupid". But it's actually true. The system is fundamentally flawed. Primarily, it simply punishes anyone who criticizes or expresses any judgment or dislike for others on any level whatsoever. Teammate intentionally feeding? Better not say anything, because YOU will get reported for "verbal harassment" and nothing will happen to them for griefing. They can always just say "But I was having a bad game" and play the victim card.
And that's the problem, everyone plays the victim card and reports everyone else for ANY amount of criticism or disagreement. And this system is COMPLETELY UNNECESSARY.
There's been a long history of very popular and major online games with open chat systems. Taking two of the biggest as examples; Starcraft and World of Warcraft. Blizzard doesn't have a system to report every little petty grievance you have with someone's chat, it's a massive waste of resources. If you have an issue, you IGNORE that person. If they do anything excessive, like ACTUAL "harassment" (not the reporting category this game has), then you can absolutely report so that ACTUAL offenses are dealt with. Somehow, all the minor bickering and criticism and disagreements magically sort themselves out when players are simply allowed to ignore or not ignore other players of their own accord.
I know that openly stating this for people who did not realize it will change nothing.
But, this one's directed straight at Riot, the reason your game has a reputation for a massively toxic and unpleasant community is not in spite of your report system, it is BECAUSE of it. When you give trolls and people who are too immature to either take criticism or ignore someone... when you give those people the power to punish others and not be punished themselves, YOU CREATE THE HOSTILE AND NEGATIVE ENVIRONMENT by enabling the rampant abuse of your unnecessary system.
If you removed the reporting system entirely, this game would become less hostile almost overnight because griefers and trolls and people who are too petty/immature to interact with others would not have a weapon with which to bludgeon others. If someone is bothering you, you can ignore them, it's very easy. Players have sorted things out online among themselves for about 2 decades worth of major online gaming just fine without a report system, and those games don't have the horrific reputation this game has. And there is no mystery what the inflaming factor is in this game.