And if you select those extremely tall Japanese people and transplant them to the United States, they will be far more likely to find success in basketball than if they had stayed in Japan. The Japanese culture (assuming) does not value basketball as a sport. Being in Japan, those athletes won't have the chance to develop their skills to the degree that they would elsewhere.

Yes, it could be said that the Japanese do not value basketball because they have historically not found success in it on the international scale, which would be because of their genetic predisposition to being shorter than even the Chinese. Genetics shape culture and culture can reinforce genetics. But it's not all about genetics. That's my entire point: there is no single variable that can claim why Kenyans run so well. But people want to say that it's genetics that make a good marathoner. That's just not the case, it takes both genetics and environment.

This is not a novel concept, but for some reason when it comes to lay people talking on the internet about sports, they don't want to admit it. The world is complex, there are shades of grey, nothing is black and white.