Why?
As far as I can tell, we’re supposed to have the following two feelings about any particular extant ethnic group: first, it has to be preserved as it is, and second, we wish it had never come into existence, because it represents the dilution, mixture, and evolution of prior ethnic groups. The Brits should preserve British identity exactly as it is, but also the Celts, Romans, Vikings and Germans should never have merged into what we now call Brits. I don’t see how you can hold these two beliefs simultaneously.
At the heart of all this is the idea that my race is something to which I have some allegiance or duty to defend, which strikes me as dumb, to put it kindly. I’m not advocating for a white ethnostate for the same reason I’m not advocating for a homeland for brown haired people. It’s not a meaningful characteristic. It’s just a physical feature.
It might be a slightly different calculus if we were talking purely about culture, but Arkansan seems to believe that people have innate cultural features based on race, since he imagined my hypothetical fifth generation Korean-American would not have any reason to identify with “our” traditions, ignoring the fact that after that much assimilation they’re as much his traditions as anyone whose ancestors came from Killarney.
All this to say: racial separatism is lame, y’all.