Can I advocate caution in using the "spam" label when closing questions?

Say someone posts a high school level homework problem. It's not spam; it's someone having totally the wrong idea about what the site is. Yes, they've been inconsiderate by not bothering to find out what the site is for. But that's not spamming. If someone leaves a question saying "Visit xyz.com!", that's spam. If someone repeatedly posts copies of the same question, which has already been closed, then maybe that's spam.

Mostly, I think that saying "spam!" is needlessly derogatory. It's an inflammatory word. Why raise the temperature needlessly? Those who have questions closed are, apparently, mostly first-time users who are never seen again once their question's closed; even so, I don't see any point in being nasty. And sometimes they're not first-time users, and the label "spam" really bothers them — understandably. I think there was some instance of that recently. If I made a genuine but misguided attempt to contribute to some community forum, I'd probably be quite hurt to be called by the same name as junk emailers.

So, I'd like to encourage people to use "off-topic" instead.

I would prefer if nothing except blatant nonsense (!@#@#@!!!!!ZŽ), multiple duplicates, and posters whom we have explicitly asked to leave should be closed as "spam". Everything else is just "off-topic".

I have to share a story about a crank...

In some Israeli forum the administrator was extremely open to all sort of people, and allowed one famous Israeli crank to post on the condition that he may only post in the confines of one thread (this actually worked).

He argued that the harmonic series converges to 137. Never he did specify why that value (which happens to be the value of the word Kabbalah in gematria). He would argue that it is impossible that the sequence itself approach zero but the sum is not finite. He never gave a clear argument and would always write his ideas in the form of a dialog which was never too comprehensible.

One day, however, he suddenly announced that he was mistaken and that the harmonic series does in fact diverge. Everyone were sure he's going to accept the fact that mathematicians knew since the middle ages. Alas, a few days later he returned and announced that once again it converges to 137...

I never knew if he was a real crank or a bored troll... I can believe either one (and various middle-grounds or other explanations which would snap Occam's razor).

But it does seem to me that it would be better if we had a way of distinguishing between "not at a research level" and "homework you really ought to be doing yourself".

We do. It's called commenting.

With the possible exception of "exact duplicate", all of the closing reasons can be taken negatively. However, in all cases except "spam" that negativity can be offset by a comment explaining the vote-to-close.

Off topic: What markvs didn't include in the bit of history, and which is the part that I like more, is that Eddington's epistemological argument originally concluded that the reciprocal should be 136, which agreed extremely well with the then measured value of alpha. When the measurement changed to be more approximately 137, Eddington managed to find a "mistake" in his original line of reasoning to correct it to the updated value, earning him the nickname "Sir Adding-One".

One should note this bit of irony whenever "crank" and the number 137 is discussed.