I think White women feel two different ways about dating black men....
Some of them feel whatever(ignorance) their parents taught them explicitly or implicitly about black ppl in general....they also consider that their family/friends/society will disapprove of them dating a black man. So there's that rejection-negativity that just may make them COMPLETELY turn OFF to even the thought or possibility of liking a black guy. They won't even entertain it in their mind.
And....some of them just don't give a damn.
They will do what they want to do. But in some cases these are not the white chicks you really want.
I'll say this, all human are attracted to other humans. You have to be programmed by your parents or by society/culture to not like or be attracted to other ethnicities. White men have been sexually attracted to black women going back slavery and white women I'm sure snuck and got it in with some slaves.