If racial groups were pseudoscience, we might find that the algorithm would return K clusters that happens to correspond to hair type groups, or eye color groups, or nose length, or height, or IQ, or whatever random group you might think of.

I've barely made any reference to hair, eyes, nose, etc. You are the one who keeps bringing that up, because you are used to people raising those attributes to try and attack the idea of race. But I'm not doing that. These aren't the arguments I made. Again, you are doing what you know. You are responding to the arguments you know how to deal with, not the ones that I am raising. I'm not thinking of any random groups. That's what you're thinking of. I never said race does or should correspond to these attributes, in fact I mocked that idea in my last post. I said that caring about those things first is monkeybrain stuff, the obvious externalities that we evolved to notice so we could make quick and dirty approximations of who we are likely related to and who we are likely not related to.