That's interesting, when I went a few years ago there was a group of National Guard troops that were also a constant source of problems. They were constantly getting yelled at by the RO's. Like you said, not following instructions was a big one, but they also had to be called to pull down and score the targets repeatedly where the rest of us hardly had to be reminded of that, they just weren't paying attention.
These folks were a bit older, so I can't write it off too much to youth, but I suspect it's the fact that everyone else there specifically sought out and signed up for this class, where they probably were sent there as part of their training. It wasn't something they particularly wanted to do, so they weren't really invested in the course.
I'll also add that despite this, it was a wonderful course. You really learn a lot and they even provide a rifle if you don't have one. Highly recommended.
Mike