Here's what I think happens and why I think people are unable to have that inner dialogue that allows their minds to be open to releasing or at least exploring the origins of their biases;
It s what I alluded to earlier in that in some cases an unwillingness to date interacially can serve as a protective measure when we speak about minorities or disenfranchised populations.
The best example I can reference would be black(specifically African American) women..in that many are quick to point out black hetero women's statistical lack of interest in anyone but black men serves a significant role in their ability to form the long lasting and loving relationships they want. Not to say there isnt a conversation there, but it completely ignores a lot of other social and cultural things that work against black women in the dating marketplace. Because frankly there's not a lot of "blackness" that I would have to squelch in order to attract a non black woman's attentions and affections, but I suspect many black women would have to hide or alter aspects of their blackness to attract anywhere near the same genuine(non fetishized) attention from non black men and thats even before you get into the european standards of beauty that are working against them further. So from all that, it can actually be a preventative measure to insist on only black men; to ensure a higher percentage of genuine interest, and to not take on an additional burden of having to teach an unknowing individual when so many burdens are already affixed.
Thats a pretty fair template for any minority to make that decision, so what about the status quo, in most cases, white folk?
Honestly, I think the same thought process is going on; a perception of loss of identity, possible loss of self, except the reality doesn't match. Its not nor ever has been a zero sum game. So what seems like an inequitable situation, a "If they cant do it why can't I" if you will, should be a recognition thats ones history and culture has already been taught and assimilated in to the social fabric, and that adding more to it can only strengthen it, while other's is actually in a precarious situation and some times needs to be preserved as is until it too can be accepted into the social fabric at large.