When I first heard that I thought some black men were over exaggerating. I do believe that many black women are afraid of getting with a black man that has his stuff together because it would require accountability. For instance if Kierra is making $45,000 a year, lives in a good neighborhood, has a good car, is pretty, and etc then starts a relationship with David who makes $25,000 a year, lives with his parents to save money, has a job as a bus driver, and etc she will not feel threatened because economically and somewhat socially he is not doing as well as she is. She will feel like the boss. She may bring her up her status if he questions her. Also some women feel like a man will not stray when in the position.
On the other hand if Kierra get's with Jamal who makes $70,000 a year, has great benefits, is in shape himself, has things going for himself, and etc she may feel threatened. Since he has his life together he may expect more cooperation and will immediately call her out if she get's out of line. This is something that I see. I've come across several black women who say that they want to make more than their man. I could be wrong but I think it has to do more with what I mentioned. She may feel like since she has more going on she can call the shots when in a relationship with a man who is not doing better than her economically.