When should questions asking for the formality of an expression be closed?

Question

I've seen several questions on this site asking whether a certain expression would be appropriate in formal writing. However, this question regarding the expression "hard to read at spots" was closed for being primarily opinion-based. I am not making an attempt to recover this particular question, but I am concerned about how future questions of a similar nature will be handled, and would also like to avoid this outcome in future ones. It was clear that something in the question was not being well regarded after the first few comments, which contained short answers and some humor attempts. Unfortunately, such behavior from the community does not enlighten me on how to improve the question.

My greatest confusion is in the close reason. Given What the "primarily opinion-based" close reason is for, it appears to me that the question does not have enough reasons for such a close: it already contains a valid answer, and the expression itself could eventually be stumbled upon by other people. If the formality of the expression itself is opinion-based, then wouldn't a close only make things worse? After all, the OP would not know that before asking.

With all this in mind, where should the community stand when handling these questions?

Answer 1

These questions are closed as “primarily opinion-based” (which you may see as POB from time to time, especially in comments) because that’s exactly what they are.

While the “rules” of grammar/punctuation/spelling are more-or-less codified, what is “formal” is entirely dependent on circumstances and what the answerer believes to be formal or informal enough in those circumstances.

Even if the circumstances are explicitly spelled out in the question, each answer depends entirely on the opinion of the answerer and how they would act in that situation: each is entirely subjective.

The canonical post on good-subjective vs bad-subjective was written in 2010. That shows that it’s possible to write a good subjective question which implicitly invites experiential answers, backed up with actual results (and perhaps potential better courses of action which were second-guessed, if the results weren’t great).

Simply asking “Is this formal enough for academic writing?” is insufficient principally because each academic publication has its own standards; and each person answering certainly does.

Answer 2

Always. Every single time. "Formal" is imaginary.

I'm only half joking. "Formal" accademic writing is incredibly diverse, and it would be very hard to concretely distinguish it from normal speech or writing. As long as you avoid text-speech (u for you, ppl for people etc.) then that's probably as strong a rule for "formal" language as you can get.

Of course individual fields or journals have their own conventions, but they can't be grouped together under the label "formal".