[dodos]

I had a professor in college who would grade you down if there were any comments in your code.

[dspillett]

Sounds like a concrete example of the phrase “Those that can, do. Those that can't (try to) teach.” Far from true for all teachers, of course.

That and “those who actually use power are likely to be those who shouldn't have been given it”!

[forgotpwd16]

Perhaps professor was fed up with over-commenting (comments made up a large part of submitted code), especially if comments were like in https://news.ycombinator.com/item?id=41506466. Unless the course is "practical software engineering" or similar, that good programming practices are a focus, and if the why/why-not parts can contribute to better assessment, an associated paper can be asked.