Riot if you didn't make such intimidating and broken champions. People would have the courage to do better.
As someone who's played games like DotA and Darksouls, can't say I can agree.
DotA in particular is significantly harsher than LoL in terms of champion dynamics, and the community there seems to generally be more polite.
Most PvP games in general are more harsh than LoL when it comes to hero/champion/player power. In pretty much any FPS you can get sniped from across the map and instantly killed with no warning.
Also: making things really easy on people tends to result in worse mentalities than setting up situations where someone is going to fail occasionally and needs to stand on their own.
Spoiled rich kids tend to have poor mentalities, people who worked really hard to get what they have usually have much healthier mentalities.