Capitalizing "Black" vs. not capitalizing "white"

This is from J.A. on electoral-vote.com.

White culture is not a thing that exists. This isn't to say white people do not have culture; of course they do. But their culture is rooted in places they can track, and nations that have long-documented histories. So instead of white culture, we have French, or German, or Italian, or Russian culture.

Unfortunately, due to the past colonial and imperialist misdeeds by some forerunners from those European nations, we have lost the opportunity for these contemporaneous African cultures to be referred to by their proper names. The cultures that the Black Americans may have called theirs originally were annihilated when they were kidnapped and sold into slavery. Further, many of the nations we see in Africa now are not nations that existed before colonization. The current nations are colonial legacy nations, thrown together in a hodgepodge of individual cultures with no regard to historical animus or alliance, meaning even if enslaved descendants were able to trace where they came from, the "nation" that stands there is likely not representative of whatever culture from which their ancestor originated. So these people were forced to create an entirely new culture during, and after, slavery. That is now Black culture, and while it may have some roots in traditional African cultures, it was created and developed wholly in the New World as a result of the treatment they faced here.