It's all about letting the music grab you and expressing yourself however you see fit. Everyone has some form or sense of rhythm. Some are just better then others and more creative with it. Most people assume most gay people can dance because a lot of us are very expressive when we get on the dance floor.When you go to a gay club what do you see? Lots of dancing and mostly because we don't care what others think.We're there to have a good time.
Go to a straight club and unless the guy/girl is really good and trying to get things started, is that moved by the music to the point where they just have to dance and are confident in their abilities or is partnered up with someone you see a bunch of a sticks in the mud or wallflowers and people just bobbing up and down out of sync.
Dancing is very expressive form or art, either passionately or aggressively, and it's very physical and not an easy thing to do. Just watch shows like "So You Think You Can Dance", "Dance Your Ass Off", "Dancing with Stars" and the like.
A good example would be to check out Carnivale down in South America. They prep like a month in advance for that festival and it shows.
Back tot he OP's question though. It does seem stereotypical but it does have some merit to it. Either way dancing is subjective and easily criticized.
One man's pretty is another man's ugly. To each their own I guess.Just have fun.