It's a cultural thing as well.
Most clubs in northern Europe, US and Asia play commercial music and close early while the typical club in southern Europe, Latin America and to some extent UK play real club/dance music and close very late.
At least in Sweden there's no tradition of going out to clubs to the early morning. Clubbing just recently got popular. People are paranoid of all types of drugs related to clubbing and rather drink their faces off in a pub or at a private home party.
have you ever been to an asian club.....?