I think there is something to having an affinity for what is most familiar. I have one black friend who is more than an acquaintance, but she lives far away so although I talk to her, I don't see her. I have a Chinese friend and am friendly with some Indians and Pakistanis but overwhelmingly the people I spend most of my time with are white. It stands to reason, knowing what I know about affinity, that I would then be most comfortable with whites. And that's not strictly the same thing as being racist (there's that inflammatory word again) or consciously discriminatory in other ways, but that affinity could conceivably have an unconconscious effect on someone who is black or from some other marginalized group, particularly in a hiring or work situation. I'd say that a lot of what's disempowering in work situations is just that - affinity for those like you (not you personally, but one).
I'm not claiming to have all answers here. I more interested in exploring the questions, and of course, I have hypotheses, but a lot of times I'm writing to try to understand something better. This is one of those times.