We were essentially told "Install R Studio, then just copy and paste these library imports and you're good to go". Your description of a vectorized language makes total sense, and that single paragraph is more of an intro to R than we ever got in class.
That said, I think the reason this happened with this class in particular is the viewpoint of (what I perceive) as the majority user's of R. Mathematics focused researchers who never learned the language, they just have done enough to get by and don't really appreciate the underpinnings, or the nuances of running an environment on a machine that isn't theres.
I can't entirely absolve myself of blame though, once I realized what was happening I should have gone and done some more foundational R learning, but at that point I just wanted to be done with the class.