I wonder how much of this is due to the fact that the programming education today comes from a top-down approach, where one starts with a high-level language with little knowledge of the underlying system or the layers of abstraction on top of which it runs. Your upper year courses is where you begin learning more about operating systems, computer architecture, and the like.

Naturally, those programmers become focused on the high-level content because that's what they're brought up with/am comfortable with.

It would be interesting to see courses being taught from a bottom-up approach, maybe not at the gate/transistor level but rather at the assembly level. Teach the basic instructions, move on to C, then move on the high level languages - I actually learned programming this way and found that it helped a lot in understanding why and how things happen the way they do.