I agree with Scott (but my comment got too long to add to his answer!).
It is not nice to see a wall of On Hold questions (I don't think however these are the majority, or that of a significant number and I insist we should leave COMMENTS and not just cast a vote and disappear. That is, in my opinion, worse), but the fact that they are there in the front page also serves a purpose: it teaches new and not so new users how to use the site.
Quality is paramount for any SE site, and that's what makes us, I think, more useful than forums. The system has reached a really nice balance where this is now one of the best places to find an answer to a design problem. To get here, we have produced an immense collection of questions and answers that is curated by the community.
I do agree people whose questions are put On Hold sometimes don't come back. Looking at the numbers, though, I can assure you that most people asking for technical things don't come back. You end up with these amazing answers with a bunch of votes that never get accepted as the correct one, because the OP gets the solutions he/she wants and flees. Someone who is more worried about design problems (workplace, work methodologies, theory) usually sticks around longer.
Finally, the place to ask for "How to fix this in Photoshop" (bugs mostly) is no longer GD.SE. It is Superuser. We had to accept these questions in the beginning because we needed the visits, the activity. Now that we have really solidified as a community of designers (amateurs and professionals), we don't need to keep these off-topic questions any more. There is a place for them, that's Superuser.
Although helping people solve their specific design problems is one of our top priorities, I think the site becoming a library of original and quality content is more transcendent. I'd say the goal of any SE site is to help an OP in a way that hundreds / thousands of other people can also benefit from it.
All new questions should go though a process, IMHO:
Does the question belong to GD.SE or to Superuser / UX? If yes, flag to migrate.
Can the question be edited and made into a better one? If yes, edit it.
Is the question on topic but terrible? If yes, downvote it and leave a comment whenever possible.
Is the question missing information? If it's recent, add a comment asking for clarification. If not, cast your close vote ALONG with a comment whenever possible.
A close vote should be the last resource. Comments are our most human interaction, we should be using them much more in these cases.