Quite a few posters pointed out that in the Japanese case it's also a height thing and I think that is unfair.
? Can you name one person who said it's a height thing with Japan? Or that every Japanese man is short...? It's about musculature, which every person does point out though. Someone with Han Cong's height but Hanyu's build simply can't succeed at pairs.
Edit: Which also doesn't mean that all Japanese men are skinny. Just that we don't see people in the singles field with a correct build for Pairs so they can switch. Unlike women who have somewhat of an easier path in terms of making a switch there. Which... Is the topic. And produced a confusion as to why Japan isn't investing in making Pairs (or a Ice Dance) a tradition in the country.