Because it is a creation of the Feudal law system. It requires perpetual allegiance, and does not allow for a subject to remove himself from the King's Obedience. Our war of Independence and subsequent War of 1812 was an overt and categorical refutation of English Feudal based Subjectship law.
What is it about overthrowing English Subject law that you do not comprehend? We BROKE with the King! Don't you get it?
“We BROKE with the King! Don’t you get it? “
Yes, I do. But the LANGUAGE of the law, used by men in 1787, was based on English common law. I have NOT said we are UNDER English common law, but that the term NBC finds its meaning in the English common law term ‘natural born subject’ - which was the normal legal term used then.
If the Founders wanted a different definition, then they needed to state one. They did not, and I’ve shown that at least one of the ratify states used the terms interchangeably for some years later.