Great suggestion! I'm all in.
First, one could upvote answers on questions that have answers with zero score (if they are good enough). Strangely, questions are tagged as "unanswered" even if they have one or several answers which is not accepted, nor upvoted. Or, if the answer is bad, make a better answer.
Second, answer questions that doesn't have answers (!). To filter out questions you want to answer, I usually brows to the my tags viewmy tags view, which makes the list less daunting and keep my (sometimes old) mind focused on this particular topic in SharePoint.
As a last resort, one have the ability to close or vote to close questions. Two years ago I started a similar "project" and started to clean up some of the old unanswered questions with the following:
As one possible step in Cleaning the Archives there is a suggestion on closing old unanswered questions. By definition, an unanswered question is
- A question which doesn't have any answers
- A question with no upvoted answers
By old question, we will define that as a question older than three months, and where the poster of the question hasn't been seen in three months. Either, users with enough reputation could cast a close vote and users without could flag the question with the same reason:
This question appears to be off-topic because it is older than three months, the poster of the question hasn't been seen for three months and it contains no answers or no upvoted answers.
If the original poster (OP) of the question returns, and want to have the question reopened - it will be reopened if it's closed for the reasons mentioned above.