I love that the phrase "for fucks sake" is known the world over. Sometimes I think I've gone to another level of vulgarity, but it would seem that if that's the case, I'm in good company
Anyway, I think people have an inherent need to complain. Political systems are structurally defective entities, and everything any governmental entitiy does will always piss off someone or other. So, politics seems to get the brunt of the bitching because it impacts people's lives through taxes, government programs, laws, etc, and people feel helpless to change anything so they just bitch to each other.
There's a series of commercials running on TV here in the states that are pretty good. In one of them, a bunch of people are standing around a sink, presumably at an office. The sink has something stuck in the drain and it's clogged. One person says to another "I can't believe someone would do this", another says "Someone should do something about this", and a third says "we need to go find who did this and make them pay!", and a fourth person walks between them all and pulls out the thing in the drain and the water empties out. The point being, don't sit around and complain, take action if you don't like something.
But then, what would we bitch about?
