Why is there a dearth of Asians, Arabs and Latinos in the NBA?

NBA has always been pushing for openness and diversity. But why is it that we only see mostly African-Americans and Caucasians in the NBA?

Is it really that there are few talents available? Maybe scouts aren't looking hard enough. Maybe there is not much investment by the NBA.

Or is it because underneath is subtle racism. It's so easy to dismiss other races with, "Asians can't jump" or "Latinos are slow". This bias is what Europeans encountered before. Being tagged as 'soft'. But they were able to shake it off when Dirk and T. Parker came along.

Curry gives small guys hope that they too can compete and excel among the best in the world. At the very least, they should be given slots in G league. With a roster of 15 maybe someday, each team will have one latino, arab and asian at the end of the bench. That will be a marketing coup.