Do students have the right to see how their papers were graded?

I doubt that this is a case of a student "offending" an individual professor and more one of rules in place that may not make sense and that you may not approve of, but still, rules.

I don't like, personally, such rules. I think they are wrong, but an individual professor has little actual control over rule making. They may not be willing to break the rules, especially if they are a junior faculty member.

Personally, I probably wouldn't give back final exams, though I did give back all others. But I would certainly let a student look over the grading. But I was bound by no such rules.

And, note that, depending on the scale of the institution, it might be very difficult to permit students access to final exams. When I was a TA, we graded Calculus finals as a group, with each TA grading only one problem. So, a student's grade was an amalgam of judgements. We were guided by a rubric, of course. But the professor didn't grade the finals and so might find it difficult to respond to exactly why a point (or ten) was lost. Smaller institutions can "afford" a more personal touch and usually strive to do so. It should be (perfect world) possible for larger ones to do so also, but often don't. And if there were a few hundred students, it is difficult to respond to individuals, just for the time it takes. Ideal. No.

Intermediate exams are a different matter, in my view, since they can and should be used to guide the student's learning. But, Rules.

And usually, by enrolling in a university, the student makes an implicit (at least) agreement to abide by the rules in place.