SO wants curation and objective answers to objective questions. Vague or poorly-scoped questions? Toss em in the bin. Questions about "best way" "best library" or "best tool for"? Subjective or not-software -- in the bin.
As a question-answerer, a frustrating question would be one that tries to articulate a bug/problem but never cites any code, compiler error or runtime error. When posed by anyone who is not already an expert these questions very often cannot be addressed without a roundtrip involving "ok, please share the code so we can reproduce the problem".
No joke -- that tip about the MCVE or SSCCE was super valuable. Unfortunately I'd bet that just the act of making this example would probably yield an answer to the person's question most of the time, without even needing SO. Novice question-askers lacked the expertise/experience to know to do this or just the patience required. I'm not faulting them, I remember what it was like to be a novice. It's a reasonable expectation to turn to a mentor and show them the code and ask them what you're doing wrong.
> Hope this paper helps me out!
> > Results: We found that regardless of user reputation, successful questions are short, contain code snippets, and do not abuse with uppercase characters. As regards affect, successful questions adopt a neutral emotional style.
This matches my experience. But I'd love to hear how the results might change if they filtered on low reputation question askers.
When HN bashes SO, I feel conflicted. I totally understand why so many folks are disappointed. But I also think that it's good for what it wants to be.