The entire atmosphere of a party is unlike anything you find anywhere else. You can find the music at a bar or a club, but people there are more concerned with how they look and if they are picking up, then dancing and enjoying the music playing. There is something very asexual about ravers. Looking at the clothing at a rave, you see a group of people whose concerns are more about being comfortable than if they can bring someone home for the night. The closest thing I can think of to the atmosphere at a rave is the one at a child's birthday party.
Nobody thinks to care who they are impressing with the way they look.
If you want to dance, you can. You don't need someone to dance with. People are there to have a good time. This is where the drugs come into play. The reputation ravers have for being chronic drug users seems well founded at first.