The child of an illegal is arguably one of the few exceptions. To qualify as a natural born subject, the parents had to be present “in amity” with the King. The children of an invading army, for example, were NOT natural born subjects. Thus, they would also not qualify as natural born citizens.
The Founders COULD have written “born of citizen parents”, or even followed Vattel and written “native”. They did not. They used a term with a recognized legal meaning. It was ratified by state legislatures that themselves used the term interchangeably with natural born subject.
There is no legal dispute.
Remember the NBC clause was an afterthought. It was not in the original draft. Originally, the President could have been a naturalized citizen. Time of residency was added for Congressional offices, and the President was then required to be citizen from birth.
John Jay thought it was an important enough "afterthought" that it ended up in our founding document. Way to downplay and otherwise duck the importance of the divided loyalties issue. You make my case for me.
The founders already defined “naturel” as native born in 1781. Obviously this was how those members who read French understood the term “naturel,” thus when the read Law of Nations, they understood “naturel” to mean natural-born, which Vattel defined as born to citizen parents. Vattel also noted that those aliens born in England were naturalized. They would have understood this as well. Just because a state legislature may used natural-born subject and natural-born citizen interchangeably to fit their own states law, has no bearing on what the framers of the Constitution were doing, especially when we have Supreme Court precedent that says otherwise. For the same reasons you argue the framers didn’t just write “born of citizen parents” they also could have just written “born in the country” but they did not do that.