Actual examples always turn out to have very sensible ex post facto rationalizations of moderation decision. Yes, there's always a good argument - this question is too short, that question is too long, this question looks too much like homework assignment, that question looks not enough like homework assignment, etc.
The point is, when you look at even few examples taken together, you realize that those "sensible moderation decision" cover pretty much the entire space of possible questions. There is no good question on SO. Moderation seems to be applied unevenly and sometimes totally at random.
This is why I don't even ask questions on SO - I have no idea how to write one to be sure I won't end up at -100 (or +100, but Closed As Not Constructive, which is SO's way of highlighting actually interesting questions).