a mod can close find support in the SO guidelines to close any question they wish.
a tightly defined, clearly written question with a single correct anwswer?
Rejected: RTFM
a question with more than one correct answer (but which almost certainly has a "best answer" which a community like SO is in the obvious best position to judge)?
Rejected: subjective; opinion-based
no axe to grind here--i used to participate in SO (50K rep, and one of the highest rep-to-post ratios)--i honestly just find it too difficult to navigate that narrow straight