Why would a kid play baseball, where he MIGHT make the majors in 15 years, when he could play hoops or football and make the league in 5? The odds of making the big league roster in baseball are probably better, but it's a longer road, and we, especially Black folks, live in a microwave society.
Regarding soccer, when I lived in Dallas, I went to several Dallas Burn games. The games were in the Cotton Bowl, and they averaged about 15K per game. Many of those fans were Mexicans from the nearby neighborhoods. Now the Burn are playing in Westlake for a season before moving to Frisco. Basically, that's the burbs, and they are FAR from any Black or Brown neighborhoods. There goes the local exposure. Already this season, Burn attendance is WAY down.
I myself play rugby. There aren't that many of us playing rugby, but a few clubs across the country have been proactive in starting innercity youth programs. Most of the high school programs right now are in your suburban and private schools, but there is SO much talent that gets wasted that it's only a matter of time before USA Rugby steps in to encourage more inner city programs, if we want to be serious on the international scene.