The reason I suggest this is that it would help separate effects caused by formerly-active users dropping off and those caused by fewer new users becoming active. It wouldn't necessarily point to a smoking gun here, but narrowing the (fairly vast) field of potential culprits is probably useful!

This is interesting, thanks! I realize you're walking a fine line here, but something I'd encourage pushing on is whether they've directly tracked the trajectories of users who were active (three months ago, 6, a year, 2 years, etc) - that is, tracking specific users, not the usual "x active users during y period" metric available on the usual charts. When I ran this in the past, I found a fairly stable fall-off in activity, albeit one that has changed over time: e.g., folks who joined in 2012 lasted a lot longer than folks who joined in 2016 and longer than folks who joined in 2011.

This gets into weird situations WRT the content license; normally we only disassociate upon author request, and only when deletion isn't desirable. Dup'd or merged, the question serves as a useful redirect to the original, which could actually do some good as a public-service message of sorts here.

If the answers can be made to fit the dup-target, this is reasonable.

Bit late for that; question and user have had a fairly insane amount of attention already; best to make the truth known.

FWIW, we occasionally get requests to purge stuff like this after it's been in the wild for a bit (and occasionally after someone's gotten fired for it). Moderators have the ability to redact post history for use in extreme cases.

I didn't ask you to defend anything, @Andrew. I asked - several times now - what the purpose of this feature request was. Y'all can already close anything you want; the request is for the addition of a specific close reason. So far, no one has mentioned hordes of students converging on the site, so I'm gonna conclude that none of you know what that close reason means nor have any interest in using it appropriately... Which is the same thing that happened on SO and why I regret ever writing it. But, my question still stands - if there's a real problem here somewhere, anywhere, I'm all ears.

Yeah, I know how closing works @Andrew. The request here isn't for the ability to close things... It's for a reason to close questions that don't demonstrate a minimal understanding. Now, I wrote that close reason originally - it was aimed at homework questions where the asker clearly hadn't read any of the assigned reading, and writing an answer sufficient to bring him up to speed would involve posting essentially a textbook. Because that's actually a problem on SO periodically. But that's not your problem. Your problem is apparently that people write... answers that others find useful?