I generally dislike "karma" and voting on posts, at least judging by couple other forums I used to visit. It seemed to turn them into popularity contests where people say popular things to get voted up, while dissenting opinion gets voted down. Basically, it's an invitation for groupthink, provincialism, and Person X bawwwing because their karma is less than Person Y They Don't Like. Still, I dunno if that would actually happen here, because the people here at least tend to be more intelligent and objective than your average person. (C'mon, you know it's true.)
Either way, it is pretty silly and pointless, but if it doesn't cause any problems, who cares?