Nothing.
Community bumps questions that have no answers with a positive score. An accepted zero-scoring answer also prevents this bumping, but the acceptance is not necessary, an upvote is enough. Thus the bumping can be remedied by upvoting one or more good answer to the question. If the question has no good answer, start by writing a good answer. If the question lacks a good answer, or a good answer lacks an upvote, Community is entirely justified in bumping the question!
It doesn't matter that the asker isn't around anymore. This isn't a forum. We aren't there just to answer questions and forget about them, we're here to build a repository of answers that are useful to future visitors. The only thing that the asker is necessary for is accepting an answer, but this isn't necessary. Anyone can post answers, and anyone can upvote them.
So what about those questions that, while technically on-topic and answerable, aren't really of interest to anyone? There is a mechanism that automatically deletes old, low-scoring questions with no answers (see the post I link to for details). If a question isn't eligible for this automatic deletion, that's a sign that it's gathered some interest and should not be deleted.
(Closed questions are a different matter. Closure — excluding duplicates — is supposed to be a transitional state. The fate of a closed question is to be reopened (often after an edit) or deleted. Moderators can and should help with the deleting, because it's hard for non-moderators to find questions in need of delete votes. But that's only for closed questions that clearly won't get reopened.)
Taking the example of Ergoemacs cuts selected region when I try to change buffer, this looks like a reasonable question about Ergoemacs. I don't know what the answers are worth since I know nothing about Ergoemacs, but at least one of them looks plausible and useful. I don't see any reason to delete it.
