Really? Your problem with “white privilege” is that the deep structural understanding that explains it is unknown to most white people (and so the term is obnoxious and hackle-raising to them), but you’re okay with “de facto white supremacy”?! It seems to me that the latter is even more risible to most white people, so convinced are they that we live not in a country that remains fundamentally white supremacist, but rather, a “postracial” one where, if any group is victimized these days, it’s white people.
On another basic point, and as @daneel basically just pointed out, you seem to think the term “white privilege” encompasses all privilege – maybe, that the people using it are claiming as they do so that other kinds don’t exist? Despite explanations offered above, you still seem to be saying that the term doesn’t make sense because in this country, both rich black people and poor white people exist, so how could the latter possibly be said to have “privilege” that the former doesn’t have?
Well, the former has class privilege, but the latter has white privilege. And if one is gay and the other not, one has heterosexual privilege. As McIntosh put it almost 30 years ago in the title of her essay, male privilege also exists. White privilege is just one kind of privilege, is it not?