So the answer is, There Is No Alternative? There's no possible way things could be different in that respect?
This summer I waited on a lot of six- and even twelve-minute batch jobs, and I spent some of those on the SO moderation queue (I'm one of the 3000-karma users, not an elected moderator). It didn't take much more than six minutes to learn that picking the interesting questions out of the flood of manure is a terrible chore.
It would be nice if the intellectually interesting questions could be left alive. But I don't think it's humanly achievable. People will post their job interview quizzes and first-year CS exercises and say, oh, mentally stimulating and please do leave open.
I don't think you could've done a better job than linking that moderation queue of "toobroad" to make your point. It was a never-ending channel of straight shit. Ranging from "here's a copy and paste of all my unformatted code that won't work, whatever that means" to "how do i use python on windows".
Everything looks easy to someone that has no stake in the solution. We get so used to being end-users that we take everything for granted, as if our experience is the natural ordering of the universe, rather than the result of all the work that goes on behind the scenes.
Read enough posts from HNers condemning Stack Overflow and you'd think they believe Reddit/HN's "new" queue is the ultimate browsing experience.
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.