Some history and background, too long for a comment:
Once upon a time the close reasons were universal across all SE sites. But different sites saw different types of problem questions, and so we were granted a set of universal reasons plus custom off-topic reasons. The question was what should our off-topic reasons be?. Especially of note is that we would get three reasons, no more (except maybe by asking higher powers very nicely).
People looking for us to solve their homework for them have always been a problem around here, so we were pretty much in agreement one of the reasons should be about homework. This ultimately left two reasons to use on non-mainstream stuff and engineering.
We had a lengthy discussion covering multiple bookmarked chats about wording the homework reason. I think we largely felt that what we came up with was the best compromise. We couldn't cover every detail in 400 characters, nor would we necessarily want to. People not showing any effort and not asking about concepts were the two biggest problem then, and that influenced the wording.
Now it seems people are noticing an increase in "this is physics; here is my extensive work; please check it and tell me if I'm off by a factor of 2" questions. Even back when we came up with the close reason, we noticed these things and moved the obscured
It's not enough to just show your work and ask where you went wrong.
up to the top of our homework policy, but those words didn't make it to the close reason. Perhaps we need them there; I'm not sure. There will have to be compromises, and we don't want to burden the bulk of people receiving this message with corner cases.
On a related note, if you can cast close votes then you can fill out a custom off-topic reason. Even back before we had this ability, I would sometimes leave comments making it clear how the question violated our policy. In particular I used the wording now found at the top of our policy:
As per our recommendation on asking homework questions, "It's not enough to just show your work and ask where you went wrong. If you just need someone to check your work, you can always seek out a friend, classmate, or teacher. As a rule of thumb, a good conceptual question should be useful even to someone who isn't looking at the problem you happen to be working on."
You can copy and paste this if you want into a custom close reason or even just a comment:
As per our [recommendation on asking homework questions](https://physics.meta.stackexchange.com/a/715), "It's not enough to just show your work and ask where you went wrong. If you just need someone to check your work, you can always seek out a friend, classmate, or teacher. As a rule of thumb, a good conceptual question should be useful even to someone who isn't looking at the problem you happen to be working on."