There's opportunity costs for those employees for having taken that job rather than another option that may have been on the table at the time.

Or having taken on additional responsibilities (loan, started a family, etc) based on having the job.

Getting a job that shouldn't have existed and then losing it again isn't zero sum.

Agreed. In my experience, being out of a job six months after starting a new one is a net negative. I can spin a longer break between jobs a lot better than that.

just leave it off your resume

Right, but then you're getting into the areas where talking about, say, a 12 month gap (4 months looking, 8 months working, then canned) instead of perhaps a 5 or a 6 month gap. It can be done, but it looks awkward, and it really sucks.

Those aren't mutually exclusive - Medium overhired but it is sad for the people who didn't make that decision but lost their job because of it.

Sure, but it seems excessive to blame them twice ;)