I suspect that I may be one of those "several users [who] keep nagging askers to elaborate" and so I will respond by writing why question (and answer) quality is important to me.
I think the way GIS SE and other Stack Exchanges work, and work so well, is because they are not forums, certainly not discussion forums. They are Q&A sites that offer focussed Q&A. This is very different to some other Q&A sites where providing any answer to any question is encouraged, or at least tolerated.
My understanding, and remember that I am but one of its 49,000 users, all of who can help curate its content, is that we seek to provide clear answers to clear GIS questions within the scope broadly defined in our Help Center. I note that you have not yet taken the 2-minute Tour that would have helped to inform you of this.
There will always be grey areas where some of our users think a particular question should be closed and others do not. We are fortunate to already have 190 users who have been engaged with the site for long enough, and intensively enough, to earn the cast close and re-open votes privilege which means the decision for a question to be placed and remain on hold (pending improvement) and later closed (if not) is not left to just one or a few people.
The questions which we want to stay open are those which will have benefit to many more people than just their original asker. We want people finding our Q&As through searches to be able to quickly understand what is being asked, so that they can decide whether it is the same as what they might otherwise have to ask and wait for an answer on. Assuming that there is a similarly clear answer then they just have to read it and get back to what they are doing.
I do not enjoy seeing questions closed, but I certainly enjoy seeing questions improved to a standard where they can be answered equally clearly. I think the process of placing them On Hold, to give their askers the chance to improve them, is best done soon after they are asked, because that is when askers are most likely to be watching their question and are available to be able to provide the necessary clarifications.
I think the quote below from We're working on a new stat to help convey the reach of your posts here sums up why we focus on the content/quality of the Q&As rather than simply on providing answers.
You gotta get this to get us.
... One thing that drew me in long before I worked here was the idea
that my effort here would help more people than it ever could buried
in some forum. Now, it's fine if you personally find it just as
fulfilling to help one person as it is to help a thousand. Or perhaps
your motivation is the challenge in solving an especially hard
problem... That's awesome too.
But whether or not the number of people who benefit from a post speaks
to you personally, it's valuable for everyone to understand that
the engine is designed to make content as reusable as possible, because it informs so much of how our system works...
See, once you realize that it's not just about the one asker, or the
four voters, but rather the fifteen thousand searchers with the same
Well, suddenly, a whole ton of things that seem prickly and
self-important, like editing out "Thanks in advance!" aren't about
being "a bunch of power-happy pedants," they're about helping all the
people who will ever have that problem to find the best answers.
And find 'em instant-like.
Today (13 Jan 2017) the numbers and percentages of closed questions during 2016 were released for all Stack Exchange sites at 2016: a year in closing. GIS was the site with the 43rd highest percentage of closures out of 162 sites. This is high, but far from exceptionally so, especially considering that during 2016 we closed many old unanswered and poorly framed questions as part of a push for Improving on 17,500 unanswered questions?
If we try to eliminate that cleanup effort by using @Shog9's second set of stats in that Q&A which only looks at questions asked in 2016 and closed in 2016 then we see that GIS has the 63rd highest percentage of closures out of 163 sites, which places it much closer to the average of all SE sites.
That large number of unanswered questions says to me that we are probably placing too few questions On Hold. The On Hold status is often much more effective, and less consuming of volunteered resources, than copious comments to remind askers that getting an answer is rarely an "ask and forget" activity; often it is only the back and forth between askers and potential answerers that distills initial questions into something that is clear enough to be answered.