Current deletion rules indicate that a 20k user can vote to delete a question instantly if it's scored -3 or less, or if it's 2(?) days or older.
- It's really not that difficult for a question to reach -3. It really isn't.
- 2 days later, it's very likely that the question will already get forgotten and won't be deleted by users anymore, unless someone pokes it with a stick. So it's unlikely for an older question to not have answers, not deleted by the system, and being found by a 10/20k user and have it deleted.
What I suggest is to completely disable deletion ability for 10/20k users for unanswered questions, regardless of score or time passed.
- The question will automatically be deleted in 9 days by the system (assuming it isn't positively scored, which is unlikely since the question was closed). If the question is positively scored, it probably shouldn't be deleted anyway.
- This disables the instant deletion of questions before the OP ever got a chance to figure out what happened. Not everyone are inhuman aliens that visit Stack Overflow (or [whatever.se]) every 10 minutes, be considerate!
- If OP doesn't fix his question within 9 days, it'll be deleted anyway.
- If the question has some serious problems, like span, abuse, trolling etc. Flagging is a possible course of action.
Right now, the system is able to do most of the work for us, so there's really no need to waste the reviewer's time/sanity, nor fuel the OP's frustration over a deleted question.