I reckon it comes down to personal preference.
OnlyFans has changed the game because, at least when you're popular, you can choose who you want to work with. Historically, it was almost impossible to do porn without having sex with white men. Even the girls you could tell preferred Black men still had to fuck white men.
It used to be only white girl who refused to work with black men but a lot of women who historically refused to fuck Black men are suddenly jumping on the BBC bandwagon.
The girls who genuinely prefer Black men seem to work with certain white performers like a Johnny Sins or Manuel Ferrara, simply for exposure, then go back to working primarily with the men they actually want.
On the other hand, the girls who genuinely prefer white men might work with Jason Luv, Jax Slayher, Dredd.
In both cases, they often work with the same performers multiple times, while being willing to work with a much wider range of people within their preferred category.
But it seems to only be some girls. let's be honest most of these girls are fucking anything