Thai and other Asian breeders breed in numbers that are much higher than what anyone in this country does. We're talking several hundred thousand fish. Just by sheer numbers there are extremely good odds of a truly special fish being born in one of the thousands of spawns every couple months. Throw into that what others have talked about that Thailand, the weather there, the water there, the insects there and everything else there is their natural habitat, food, ect.
Are they necessarily breeding better quality fish though? Probably not. The conditions they breed these fish in are extremely tough, and are based around a quantity rather than quality approach (not that i would do it any different if i lived in that part of the world). One breeder with a very small operation, paying extra attention to selection of breeders, and extra care to proper feeding is going to probably produce more quality fish per spawn. But are always going to look pale to the sheer numbers of fish the Thai breeders turn over. They will make more quality fish just by accident.
Now also factor in the IBC members. Some of the best fish in the country, and perhaps the best you will ever see, but they pretty much only go to shows, and get sold at the auctions at these shows. I haven't really looked that much at types other than PK, but in that category on Aquabid you will be hard pressed to find a fish by any of these breeders.