By that argument Nazism was a product of its time too. A lot of Western Europeans did not see nonwhite people as fully human then. Some went as far as seeing them as animals or soulless. Western Europeans were already committing genocide against non whites via the colonial enterprise, man-made famines etc.

Entire fields of science (race science, "phrenology") were created and religious philosophies were adjusted to accomodate this inhumane worldview.

I wouldn't see Nazism as the antithesis of Western thought at the time. If anything it was the natural progression of some of the darkest aspects of the Western worldview. Hitler is largely vilified for engaging in imperialism against other Western nations. If he had quietly committed genocide in a colony located in the "global south".. I don't see how other Western nations take issue with that since that is what they were doing at the time.