It's not about discounting talent, it's just quite obvious that there is some kind of "special sauce" missing.
If we look at the former Yugoslavia, there is a very steady trickle of NBA-quality (ie getting regular minutes) players, and occasionally Hall of Fame-level players. How can China not produce any players of even just the former-type in decades with the enormous talent pool it has? As I said, it somewhat defies statistics...
I imagine the same such issue exists for soccer/football.
In the Sports thread it was discussed that parents are wary of the Sports academies having a bad academic reputation, so if things don't work out athletically, they are afraid of handicapping them for university. To alleviate this concern, more after-school clubs are being established, but it is a fairly recent phenomenon. Even then, parents are concern with spending so much time "playing games". I am not familiar enough to elaborate further on this topic though.