An all black league would yield an all black audience. Whites, naturally, would not be welcome at an all black game.
Can you imagine a respectful, peaceful crowd at such a game? Can you imagine the crowd restraining themselves after an upsetting game? I can’t.
Can you imagine gun fire & unrestrained violence at such a game? Can you imagine the game itself becoming ever more violent? I can. Call it “knockout” basketball.
Raise you hand if you would like to work security at such an event.
Some may say these statements are racist, but I say they are born out of the recent history of American black culture & the violent, segregationist direction it is headed.
It won't be an "all-black league" but it will get real close. For awhile, it might even be quite successful. But gradually, it'll become a minority sport, a bit like professional Soccer never taking hold in the US.