The problem with blacks being unable to catch cabs is how much black cabbies distrust other blacks. Years ago that has-been actor Danny Glover tried to make a stink about this, and the story died quickly when investigative reporters noticed that most of the cabbies passing blacks hailing cabs WERE BLACK THEMSELVES.
I remember this. Quite a few black men have found out that the biggest threat to their happiness is other black men. Occasionally someone slips up and admits this in public (Jesse Jackson, Chris Rock, Richard Pryor...)