I actually might be able to shed a little light on that! A few months ago on here, I had an interesting exchange about this issue with someone working as an English educator of some sort. She argued that it was specifically the tragedies black people have endured and the injustices that they continue to face that they deserve a capitalization that "white" people, for example, don't. I think she might have even cited a source or two. To me, the idea that any race(s) would take solace in a capital letter is still a little ridiculous. You're right that it implies a hierarchy.

Thanks for sending this one in, Matthew!