But the too-broad questions aren't usually very interesting. Most of them are just pure crap. If you have enough SO karma, try https://stackoverflow.com/review/close/?filter-closereason=t... — what I see just now is someone who wants help with his java/spring thing and isn't very detailed about it, someone who's "been trying to learn how delegation" works, someone who "would like to know how can i mock diffrent user request behavior pattern" and those aren't unusual. The intellectually interesting questions are unusual in the "too broad" morass.
If people are to moderate SO, the rules have to be simple and quick to apply. Of course people don't have to do that, but I fear that without moderation, the interesting questions would get no answers because they would be completely flooded by questions like those three. So the open-ended, intellectially interesting questions lose either way.