Why people in NA servers are so mean

I really don't want to offend anyone, but people in NA servers are so mean. They flame in chat all the time, if you underperform even in normal games, they will rage at you and even report you. I recently played kalist for the first time just to learn her mechanics and as it's reasonable i underperformed, everyone started flaming so bad as if i wasting them so much. I know i could be playing vrs bots but bots don't behave like humans, they don't dive and they make pretty standard plays, so pvp is a different experience. You see it everywhere, people always get mad if you 'ks' them or even if you make a mistake. I am not sensitive at all, i enjoy flaming if not in ranked matches, i like when people rage and say funny stuff in chat and sometimes i take part just for the fun of it. I don't get offended, these people don't even know me but the thing is in ranked games flaming can make the game go wrong so i don't like it.