I wonder why League of Legends is so toxic

I've played this game for almost 2 years now and I have to say this is one of the most ridiculous games to exist. Players think that trolls, feeders and toxic players should not reported in norms because they are "normals" and not ranked is ridiculous as hell. And that free easy 4v5 or some occasions 3v5 don't report the people like why? I really wish this game wasn't so crappy with the community I though call of duty was bad. You can't have fun is this game anymore one simple mistake and someone flames on you.