How come WWE does not treat a lot of black wrestlers right?

Like now and in the past a lot of black wrestlers like MVP, Shelton Benjamin Kofi Kingston R-Truth up until this year they all really didn't get that much of a push not a lot of black wrestlers were world champion Ron Simmons was not really a champion for long he hardly is known for wrestling all he's known for is saying DAMN but why do you think wwe does this to black wrestlers?