why should questions with only one answer be deleted when they expire ? why not a yes or no vote?

The problem is that the asker never comes back and they drift into Q&A limbo. I agree that there should be a way to evaluate if that single answer is a good one, but of course the current voting system couldn't deal with single options. My suggestion is bring those questions to the surface periodically, either 1) randomly or 2) when they're visited by the questioner or answerer(which would be a signal that somebody cares about them).

They will not get new answers if they're buried in page 2,345 of the site.

The asker should either vote it as a best answer, delete the question, or extend the expiration date. There's just too many of them.

The asker should have the ability to pick the answer if it is good or not. If it is a bad answer then it can be ignored. Sometimes questions are answered the best in the first answer so people see it and realize there is no reason to respond, except to get extra points.

Why not automatically make it the best? That'd be great for those of us who wind up being the only answer on there! ;-)

i don't give two flying f###ks what you think of my premise !!