I’ve never thought about the reasons explicitly, but in my own writing I do not capitalize the W in white but I do capitalize the B in Black.

I think subconsciously, having been exposed to the writings and thinking of white supremacists and self-described European chauvinists, I was loath to emulate them.

But mostly, I made the stylistic choice without thinking a lot about it. It just seemed appropriate to de-emphasize whiteness.

But in any case, I think it’s pretty crazy that white people would get caught up about this. If they’re really all hyper over whether or not you capitalize something, I’m afraid I’d have to question where their hearts are.