The first thing to remember here is that the site exists to help people use TeX. In the end, provided that happens other factors (such as stats) are not so important. At the same time, of course, we want to make it as easy as possible for people to find the information they want.
In the StackExchange model for a site, the idea is that good questions should be kept open and answered whilst poorer ones are closed but can be edited and improved. There is a question of timing: whether it is better to leave poorer questions open pending edits (as we've tended to do) or to close and await edits before reopening (as on the main StackOverflow site). However, in either case the situation is you need the original poster to clarify the question in order to improve it, or you need someone to take a guess as to what they mean. The latter is obviously more risky in terms of helping the OP but may make the question more useful to more people! What is certainly true is that while we can ask the OP for more detail, there is nothing we can do if they ignore such a request other than possibly close the question.
What's notable here is that closing questions isn't supposed to be a 'negative' outcome (in terms of site stats). What it's supposed to do is mean that open questions are good question, whether or not they are answered, and it's these open questions that hopefully should be searchable.
I think it's worth noting here that the classic difficult-to-search question type is the 'How do I draw X?'. These very often don't have any text giving away the nature of the diagram required, and are often very focussed on the needs of the OP (lacking generality). However, we've tended to tolerate such questions, partly as answers are often possible and partly as there is an assumption that we first want to help the OP, and only then worry about the wider audience.
In terms of what we can do to help users ask 'better' questions, we are somewhat limited. The mods can edit some parts of the Tour page but not all of it (we can edit the intro and what to ask/not to ask). The way the Tour page is set up it does not feel to me as if detailed 'How to ask a question' ideas belong there: I'm struggling to see where 'Consider adding a MWE' would fit in.
We can also edit the first part of the ' What topics can I ask about here? '. You'll see that in the latter there is already a line about providing a code example if possible. What it doesn't say is that one is required: there was a suggestion from the Powers that we might want a custom close reason saying more-or-less 'Off topic as there is no MWE' but that seemed far too prescriptive. I'm sure we all appreciate that there are some excellent questions with no code in them at all. Moreover, I'm pretty doubtful that most people sit and study these help pages before asking questions. My usual impression (certainly my own experience on other StackExchange sites) is that you (hopefully) do a quick search for what you want, and failing to find it post what you think makes sense and hope for the best!
<whatever TeX stuff> site:stackexchange.compossibly and if I'm looking my own answers add percusse somewhere. Hence people would probably end up there if the answer has the buzzword that is sought after. Hence I also frequently end up here from a search engine. In that regard it doesn't reflect the user experience. – percusse May 28 '15 at 21:34