I'm struggling with the intended scope of "not useful" used in the question downvoting tooltip.
For question upvoting purposes, I generally interpret "useful" personally. That is, I upvote a question if I actually get "use" out of it. That means I don't upvote many (presumably) "quality" questions because they deal with domains I have no real understanding of, let alone "use" for.
For downvoting, however, this strategy doesn't work. The fact that a question isn't useful to me personally generally doesn't mean it's not useful to someone else.
So with respect to downvoting questions, what is the intended meaning of the "not useful" tooltip? Not useful for the entire community (i.e. no reasonable person would benefit)? Something else?
I'm particular interested in any intended scope that is not within the "vote-to-close reasons", as I've recently seen statements that there are reasons to downvote questions (even on SO) not covered by "vote to close".