I think that SOMETIMES people who are playing on higher spec rigs either have "better" games they can play instead if they get tired of Toribash, or they aren't as concerned with games that are purely skill based, like toribash, and prefer to play "level up to win" games, like Skyrim or Sword Art Online :P.
People with shite computers often are not as concerned with graphics or content, and enjoy games with active, friendly communities associated with them.
This is of course just speculation. I think many of the really serious players have good spec rigs.
In the end, I think that although there may be a trend shown between computer-goodness and rage-quittiness, the main thing is that if you enjoy competitive skill games like Toribash, you don't really care about graphics all that much. So it won't matter to you whether your computer can hack NASA, or if it takes twenty minutes to open MS Word.
btw, I play on a HP 620 Laptop which does in fact take more than 2 minutes to open chrome