Oh, not scientists as we know them, but Medeival scholars trying to place those ancient mysterious (at that time) structures in the context of what they did know of the history of that time -- which was mostly through bible stories. And since they had certain unquestioned assumptions, they weren't too rigorous about holding their speculations in check.

Actually, they bear a closer resemblance to the "scientists" who say aliens built them than to actual scientists who actually learn to read ancient Egyptian and study the structures and artifacts directly.

But since Dr. Carson doesn't know it, it must be that nobody knows it, so why listen?