Let me add this, which some people might not like hearing, but it's truth:
Men like soft, gentle females. Yes, some women are louder and more boisterous by nature, but a woman can easily be desirable to men as long as she maintains some demeanor of gentleness and soft femininity. Imagine a black chick who does her hair nicely, wears summer dresses, and smiles warmly at you. Sounds good, right? I'd like to get a piece of that myself.
But many black women - not all, but many - come from harder backgrounds with deadbeat dads and surrounded by less-than-wholesome thugs or hoodlums. And in these hard circumstances, soft femininity is not an advantage but a weakness. It WILL be exploited by the thugs and jerks around her. They'll take her money, sponge off her, and knock her up before ditching her. Happens all the time.
So black females in such circumstances have to harden their hearts and become rough. Soon, that's just who they are. The soft femininity seeps into the cracks of their hard life and hardened heart. Men don't like this, unfortunately, and so these women end up relatively undesirable, sexually-speaking. Is it fair? No. But what can you do?
This isn't purely a race thing, btw. The same is true of poor white girls in trailer parks, or Latinas in the Barrio. (Although Latinas seem to generally resist this more. Perhaps it's the stronger family bonds in that background.)
Just some observations.