You can see my reply to the parent comment. I always sit down and talk with the students, but for us to talk about the code, we need to be able to read the code. Unneeded comments make it significantly harder to read code.

First time we talk about why I don't want "the what" comments, only "the why" comments. If they still do it in the next handin it's a fail unless they've explicitly provided me with a reasonable reason to do it.