> Deletes every single thing the student contributed

Yes, this is what I don't understand. I think other commenters here haven't actually realised this is what happened, as well, and aren't seeing the problem.

One thing I find annoying about Wikipedia is that there is basically no owner or point of contact for the content. So, if I have an idea for a change, I can add a comment to the Talk page for the article, but it'll often languish there for months (years) on some pages. I've never gotten a sense of 'community' there, and although I've made 500+ edits and contributed new articles and been a member of a 'WikiProject' I still wouldn't class myself as a 'Wikipedian' nor would I know how to assign that role to someone else.