It does applied to all. However, in the Dota player base (at least in Malaysia), the percentage of anger problem player is a lot higher than any other game.

Mainly due to the influence from Dota player and the nature of Dota that is easier to learn. As such, a lot of non-gamer player will play Dota. I have noticed a lot of my friends who only played MMORPG or don't even play any game would try out Dota. It would end up with too many bad qualities(bad anger management, bad learning behavior or such) player, as compare to true gamer.