You're absolutely right, this is a big issue. I really appreciate @machead3's proactive approach. He's running into some rate-limiting bugs with the system we put in place to prevent spammers from taking over the site. I'm actively investigating those.
I think that answers should be reserved for actual information. If I landed on that question, how can / should I vote on his generic 'Post more details' answer?'
I propose an alternate solution: Vote the question down, and leave a brief comment saying that you can't answer the question without more information. (If possible, link to a similar question that has been answered because it had more details.)
Once a question's score drops below two, we'll change our algorithm to remove it from the Unresolved questions list. If the user does edit the question and adds more information, it's easy to reverse the vote.
What are downvotes good for, if not to call out unanswerable questions?
