I agree that something is obviously badly wrong at that company. Without knowing more details, I can't really offer an opinion on how to fix it. The "only hire black people" version seems kind of lazy--papering over really serious attitude issues that are going to be bad for the company. But details matter, and I don't know enough to say.

However, I do know enough to say that the argument M.L.S. made was wrong. But I think I found old demographic numbers--you're right that South Africa is around 10% white now, which is actually a smaller fraction than of blacks in U.S. (though roughly comparable). Thanks for being specific and thereby catching my mistake!