Jus soli isn’t a law of nature, but it is a law of morality. Anything less is effectively the creation of a caste system of full citizens and second-class citizens purely depending on who one’s ancestors are. This is not a hypothetical; many countries historically have been and many still are in such situations due to the lack of birthright citizenship. The fact that most of this map is red is nothing short of an affront to human morality.