EU players are usually better at PvE and more into it then US players. For example all the world first heroic PvE boss kills in WoW almost always go to European guilds. Might be do to the fact there is a lot easier ways to not work get goverment handouts so you can play the game almost all day. But if they ever become good at PvE in a game like WoW they just make their living off of sponsors, mostly tech companies. Then it becomes their job to get world first kills.

However when it comes to PvP thats when US players dominate.