Are you turned off when you find out a girl “only dates black guys?”
I think there are two reasons this comes across as trashy. One is that they are almost always the “ghetto” types who sell dime bags and have mixtapes at best, and actually are delinquents/criminals at worst. They are never normal, suburban middle class guys.
Secondly, seemingly the only logical reason a girl would “prefer” or exclusively date black guys is because they are rumored to have bigger dicks. There is literally no other race that girls exclusively date with any kind of consistency, nothing like this phenomenon.
It probably doesn’t help that these girls are almost all trashy themselves, tramp stamps, chain smoking, single moms under 30.