Well I haven't done any teaching, but I'm sure a good course should clearly explained that there are two main aspects to learning and using an arduino in projects and that is the whole software side (PC based IDE, arduino C/C++ sketch language programming) and the whole electronics fundamentals part of interfacing to real world input and output electronic components. The first is specific to the arduino platform and the second is more general and fundamental.
I sometimes think typically (at least in the arduino tutorials I've seen) the first part is covered more and better then the latter and the latter is generally just exposing the students to some simple example wiring diagrams and maybe some basic rules to follow rather then any attempt to start at least a structured basic electronics fundamentals curriculum?
Lefty