There aren't as many good MMA camps available for Asians as there are for Brazilians, Americans etc so they have less options. That and they tend to be less athletic.
Many of the better Brazilians train in America anyway. Yes Blackhouse is headquartered in Brazil, but they also have a gym or 2 in America.
Hmmm....I wonder why there are few top Asian MMA gyms when the sport was so well-excepted and big before the UFC was ever big? Hmmm...probably because they have few good fighters to start and teach at camps. Or simply focus on the wrong aspects of MMA.
Hmmm why does Brazil and America have the best camps? Probably because Brazilians and Americans have yearly had many of teh best fighters in the sport. Even back in PRIDE (A JAPANESE PROMOTION) Brazilians had guys like Arona, Nog, Wandy.....other than Sakuraba, where were the great Asian fighters???
It can't be "oh they have no good camps". Well why don't they? The sport of MMA was accepted well before it was in America. So why are they so behind?