I think it's equal parts "I don't want to sound like a jerk" and "this guy is my age, we should be buddies." I can't really think of a way someone with one bar (or one and a half) can talk to a Cpl with more time in than said officer, and tell him "that's Lieutenant for you, Corporal" or such without looking like he's full of himself.
I think that the younger NCMs (and young officers) haven't been taught where the line is and where they should draw it, and that causes confusion. There is some measure of word-of-mouth, this-is-how-it's-done advice given, but no formal information given as to how one is expected to act.
I'd assume the problem is even worse for us RMC types, as the only NCMs we encounter on a regular basis are instructors and are treated as superiors. The other problem being that most NCOs on campus are that much older that we wouldn't hang out with them in the first place, whereas when we get to our unit, we'll have guys and girls our age under our command and we'll most likely feel more at ease with them than with the other officers, who will often be older and more experienced.
I don't think I can throw in my two cents, so consider that my free opinion... and you get what you pay for.