Widespread HARASSMENT in League of Legends

Hi, at the begining i would like to say that i like playing LoL because it's a fun game, but 95% of the games that I play with random players turn out to be a hateful exchange of views on chat. So the other day when i started playing a random match 5 minutes into the game the trolling started. A player who was doing verry poorly started to insult every one close to him, i tried to ignore him but after reading that i should kill my self or that he hoped that i get cancer, there were allso some insults to my mother I had enough. I excused to other players that I dont want to be harassed and im quiting the game and so I did. Now when i start the game i get a LeaverBuster Warning telling me to agree that I will never disconnect while i play. So ok, i have two options either i agree not to disconnect and be harassed during gameplay or not to play any more. You will say that i am making a big deal out of nothing and i could just ignore the chat but then i am risking to get a not communicating with other players report. The game mechanics that Riot introduced in this case basicly only gives you the option to play and be harrassed or dont play at all. You can say that the reporting system punishes bad behavior but clearly that is a joke since you get harassed. Dear Riot i know that You dont care about those things and cannot ban those players from playing because You would have to ban about 50 % of all the players and 50% less players means 50% less income. I just have one question dear Riot, I dont want to be harassed, why are you punishing Me for it ?