Today, I was looking at my rep history, and I noticed a -20 on it. Since I'm only an occasional user of stackoverflow, this is a noticable fraction of my total rep. So I thought I'd look into it to see what my mistake was.
Looking closer, I had an answer addressing a question informally, with a few illustrative details. And this question had an answer that someone later on posted which was much longer and more detailed and more turgid than my post. And a diamond moderator deleted my post. So, perhaps my post was deleted because it's a duplicate of the later answer. Or perhaps someone decided that my post was too chatty? Or perhaps they decided that it did not even partially answering the question?
And, if this kind of ambiguity is a part of the way that stackoverflow is supposed to work, I do not currently have any basis for objecting to it. (It's not like stackoverflow rep has any real-life consequences for me. For me, rep is only a guideline for suggesting how I contribute in the future.)
Still, I literally do not understand what happened here, so I can only make assumptions which could easily be invalid.
So.. perhaps deletions of upvoted posts should include some kind of declaration about why the post was deleted? This could be as simple as a set of checkboxes which correspond to line items in https://stackoverflow.com/faq#deletion where at least one checkbox has to be checked before a post can be deleted.
Possibly related topics include
and How can I audit deletions that affect me? which highlights a different issue (deletion of questions) where deletions might be losing information (information which might be beneficial for some people that contribute useful content).