Spot on. I've asked friends who were clearly enjoying themselves why they don't bust a move, and they say, "Oh, I can't dance." That's always tickled me. "Can't dance" should be a label reserved for quadriplegics. It's possible to be "bad" at dancing, but that's a pretty subjective term. Someone doing the worm might be more fun to watch than someone else just waving their arms back and forth, but who really cares? It doesn't matter how old you are, how white you are,, or what music gets you going, you can dance. You're absolutely right though, it's a question of cultures and comfort zones.I don't even think it's necessarily that the focus is put on the DJ. Rather, it's that these people dont know how to do anything but watch the DJ.
One of the great things about going to a club with a bunch of like minded people is that it doesn't matter how you dance. You just move your body in the way you feel the beat compels you to. Even if you've never danced before, a basic dance can be just an extension of bopping your head. All you need to do is twist your shoulders from side to side at the same time and bounce on your legs a bit. Voila, you can now dance at a club. Of course, it'll be years before you're throwing moves like this.
OMG that video is A1 lol. But yes, your point is valid.