The reality is some countries are just flat-out better at certain sports...
This.
There many other caribbean islands like Jamaica. Yet its Jamaicans winning all the gold medals.
There's just as much money in high level soccer as there is in the NBA or NFL. If potential track stars in America are driven to other sports based on potential earnings, then the same can be said for Jamaicans when it comes to soccer and crickets (which are the most popular sports there).
Its comical that people are trying to reach for explanations to deny a simple fact. Jamaica dominates sprinting. I have no idea why. And there's really no logical explanation. But it is what it is. PERIOD.