I don't think it's about being able to train full time Oni, Chinese kids still go to school, and I don't think it's gene pool related either, more about culture.
Our best athletes go into swimming, track and field etc because there is better funding and more exposure at a school level, there aren't to many schools out there that expose kids to Olympic lifting (IMO they should, even if the kids don't stick with it it would help their track and field, football, basketball etc athletes.) Add to that you don't have talent scouts going around looking for kids to lift.
I'm sure you can see results from the Russian/Bulgarian/Chinese programming, but that is different to the method.
Something else he also mentioned was that the Russians are very protective of their kids. They won't let a kid do something that could cause potential harm. He use ice hockey as an example, kids in Russia aren't allowed to "check" other kids (into the wall, glass etc) they find it quite barbaric that kids in USA are allowed to do this and think its pretty disgusting stuff. As a result their kids only prepare for weightlifting without actually performing the lifts until they are 15-16yrs.