For most of their history, most prestigious CS programs were teaching computer science that often looked a lot like math and tended to use non-commercial tools like Scheme/Lisp to explore principles and theory of the field.

You didn't take those majors at MIT or Stanford to learn to code COBOL or C or Java, although in upper division classes, you may have started learning how those languages worked and may have begun working on advanced-theory projects like compilers. Students in those programs were understood to either be future academics or auto-didactic enough to pick up the vocational skills on their own. (Admittedly: this did mean that a lot of top tier CS grads were pretty awful software engineers)

It's only in the last couple decades that these programs, and the less prestigious ones that try to emulate them, started reluctantly admitting that that students and administrators saw them as vocational schools for getting high-paying jobs in tech the year after graduation. Many of their senior professors and alums were not thrilled about that.

I'm surprised that you found your professor's position unfamiliar or confounding, because it's still pretty widely held in departments/programs that specifically identify as "Computer Science" rather than Software Engineer or Computer Engineering or whatever.