 Because hip-hop really started as a byproduct of city culture. Basketball is very much a city game. It did take place in gymnasiums, obviously, and it did take place in the suburbs. But basketball's biggest influence is in the cities. You don't need much room to put up a basketball court. You don't need much room to put up even a hoop. The game really was a way for city kids to assimilate into American culture, especially Jews and African Americans.