I did a CS degree 20 years ago. Databases, concurrent programming, and network programming were all 4th year electives (I took network, AI, and image processing personally). But something not being included in a core curriculum doesn't mean someone can't learn it.

My curriculum was: Year 1: Intro Comp Sci / Year 2: 2 courses in Logic, 2 courses in data structures and algorithms / Year 3: 2 courses in processor design, 1 course in finite state automata, 1 course in parsers / Year 4: a course in ethics, a course in team programming (which covered UML and version control), and two electives.

I believe a major was 14 courses so I'm missing one, or it may have been it was three electives. I didn't take databases because I was already a paid sysadmin before I started college and mostly at the time database courses were just ten tedious weeks of normalization crap.

Also, treat your interns better. The reason to hire interns is because you plan to devote some of your resources to help them in their professional development. Stop asking what you can get out of your interns and start asking how you can best give something to them.