I really don't want to sound rude, (I'm not trying to be in any way).
First: We only have the information that the question asker gives us to work with. So questions that don't include hardware information, version information and aren't descriptive don't usually get answers. There is very little we can do about that.
The questions on the front page are only questions that have been asked or edited recently, so of course most of the unanswered ones would appear on it. If you search for isaccepted:yes you will get a list of all accepted/answered questions.
Doing the math from that screenshot, we actually have over 30,000 questions answered here and we're working hard on improving that.