The title/hover text for the upvote icon for questions reads "This question shows research effort; it is useful and clear". While clarity is relatively easy to evaluate from the post itself, determining research effort would seem to require at minimum doing a web search unless one knows that the subject is well covered in common sources. Usually I do not bother with a search (and my Google-fu is not reliable) even if I intend to answer the question.
(I was surprised that a search for "fiction avoiding overuse of pronouns" found a few reasonably appropriate pages in the first 20 results, but even the best page, Ask the Editor: How can I cut back on the abundance of pronouns in my writing?, did not seem to provide a thorough answer and took a different tack than my answer, which was more palliative.)
Usefulness seems even more difficult to evaluate. While more specific questions might be less useful typically, some specific questions are obvious cases of a more general problem. Asking about the general problem may be quite useful.
(For answers, usefulness is much easier to evaluate.)
I ask this because many questions seem to receive no upvotes even when the question seems reasonably clear and somewhat useful. Not upvoting such a question and yet answering it seems a bit odd.
Weak questions which might appropriately receive one or two upvotes are especially hard because being the first to upvote a weak question takes some boldness but after being upvoted it is not as clear that the question deserves a second upvote.
"Good subjective" questions are probably more common on Writers than some Stack Exchange sites, but such questions are also more difficult to evaluate.
When should a question be upvoted?