Originally Posted by GranGrimorie
hmm so fair to assume that high damage damage champs attract toxic sorts and those that play the reverse, supports are well mannered? O.o
It's just something I made up in my head, but I assume this is because these are the sort of people that need to feel satisfied by thinking they are important. Getting kills alerts everyone in the game, as the announcer says "AN ENEMY HAS BEEN SLAIN." with the summoner's champ picture and the victim. This in turn strokes their ego, which reinforces their idea that they are important and the MVP. They don't want others to get kills, as it shifts their idea that they are important away from them. This is why most burst, damage, assasin, etc players are egotistical arrogant snobs.
However, support is a role that, from my experience as playing them, gets satisfaction in feeding teammates kills and trying to cooperate with other players to make plays. These people want others to succeed and want to be more of the foundation for the team. Just from personal experience, watching streams, vods, etc.