In this case, I think using the term racist here is diluting the term and causing confusion. I think it’s better to us the anthropological term here of tribal, at least in your first and last paragraphs. If everyone is racist then I have trouble not considering that a normal part of being human. It seems like railing against people who breath or something. If we’re biologically programmed to be this way, then we need to stop trying to claim people are bad for their biology, and at best we’re now going to say there’s an acceptable and normal level of racism on the spectrum that everyone is on.
I don’t think that’s a great framing, and avoiding that framing in my mind means not claiming that everyone is racist.