Anyway, please tell me all "clans" are not like that. These guys were arrogant pricks whose lives seemed to revolve around playing games. No, not "playing" games, winning them. At all costs. Even at the cost of fun.
A clan is just a little communty of gamers.
How they play depends on the clan, and the goals of the clan.
Most clans are about competive gameplay, which means they try to get as good as they can. So you were simply not really good opponents for them. Can´t you understand why someone may act like an arrogant prick if he can beat you even with closed eyes? The only fun left in such a game is making jokes, cause its no challange for them, and no fun for you.
Simply the wrong ppl that play at this lan party together.
So please stop complaining about the so called "pro-gamers" or "powergamers", they are still just all looking for a challange (ok some for the money aswell), and it is as frustrating for them as it is for you if they get the wrong opponents.
Sure you can meet there real idiots aswell, but what is so special about an idiot?
You meet more idiots that are not powergamers than you meet powergamers at all
simple cause there are alot more players that do not have the time, will or skill to play at those high levels.