Do you have a cite for that? It's a hamburger menu, which is by far a more common menu paradigm in the modern world. Do you imagine some kind of "casual user" who... doesn't have a phone?

I repeat: the menu bar is a dying abstraction, preserved in a consistent form only on the Macintosh (even iOS has no equivalent), because it's presence is unavoidable. Users of modern apps don't see it used consistently, so it's absolutely not surprising that Apple's designers aren't doing it either.