Good explanation @austinmshauri - but it sounds like it might have initially been a bit arbitrary in how that came to be. Good ol’ feds-- clear as mud! It just seems … peculiar that someone can live in a country for a while and identify with their culture/ethnicity, yet others cannot. As I mentioned earlier, my DH was born and raised in the far east. But he cannot (would not anyway, but cannot) claim any cultural affiliation (you wouldn’t know that form all the furniture, decor, etc we have from the far east in our home).
There is also often the classic debate about Judaism as a culture vs a religion.