Okay. Personally speaking, as an African-American woman I feel that a few (not all, just a few) white guys, not having any other reference point, believe and accept the loud talking, neck snaking, finger wagging, bad grammar having woman that was generally portrayed a few years ago on television and movies. I mean, it seems strange but a lot of people's perceptions are gleaned from media because they have nothing else to go on which is pretty sad if you think about it. Now we're starting to see Black women portrayed as intelligent, successful and highly educated on TV and film (Girlfriends, Two Can Play That Game, just to name a couple).
Having said all that, I think that sometimes white men feel like they can't handle the ghetto-hoochie rap princess they *think* we all are. Not that they're afraid, they just don't want the drama. I can totally understand that, but all black women aren't like that. Personally, I'm a college educated black woman in her VERY early twenties with a degree, my general securities license and a killer job in the healthcare sector. I don't have a bunch of kids and baby's daddies, and my hair and eye color have never been anything other than what I was born with. Most white people assume I'm a white woman when they speak with me on the phone and are surprised, sometimes speechless, when I show up to a meeting or assessment. It's pretty funny, really.
All that is to say that it may not be always that black women are not attracted to white men, but maybe some white men are intimidated by what they think a black women stands for. I've also thought in the past that since black men are so lauded for their sexual prowess and, "ahem", endowment(which is not true for all of them, trust me!) that they may feel they won't measure up in the bedroom. That may also be a reason on the part of black women's unwillingness to "go there" with a white man. I wouldn't mind dating a white man...but he'd have to be really cute...and rich. See? My standards have no racial barriers!