I should have been clear that I lean toward your side of the issue in that a blanket policy for the entire term does seem a bit extreme but completely without value. If I were pushed to defend the instructor’s policy of a particular editor, vi is nearly certain to be on any Unix installation. Not necessarily how I would (or have) done it, but the approach is not without value.

My preferred Unix editor is the vi family. I wonder whether emacs people are less sympathetic.