It’s not the race, it’s the culture. On average, the majority black and hispanic cultures don’t place much emphasis on learning. Chris Rock even said it, something like going back to the ‘hood with a master’s degree and someone saying “Oooh, you have a master’s degree, but can you whoop MY ass?”
Why have races evolved different cultures? I think in part it's because the members of a race emphasize what they are good at, which will also tend to be what they like. People who aren't that smart will not enjoy academic work or leisure reading as much as more intelligent people, on average. Would black youths emphasize sports as much as they do if they were not good at them or did not see the example of many successful black athletes? Jews have a culture that emphasizes education, but European Jews have an average IQ of 115, so this may be another example of a group playing to its strengths.