> Only smart people could be convinced of such foolishness. A classification system as simple as 'race' may not provide an accurate taxonomy for all scientific purposes. It does however provide a sensible abstraction which has persisted uniformly across cultures and time because of its utility.

Notions of race (either at the high level of what race in general is, or at the lower level of what defines specific races) are not, even approximately, consistent across either space or time. I mean, I get that it makes building arguments much easier if you can start with your conclusion and just invent whatever premises are convenient to support it, but...