Questions typically go unanswered because they have a poor title or an incomprehensible or overly long description.
Or the question was posted over the weekend, when fewer people visit the site.
Or the question is difficult and no one has a good answer.
There are many reasons. Frontpaging helps keep the nodes alive, but I agree with you that the system needs to be fixed. There should be some way of viewing nodes with fewer replies or identifying nodes you would like to see other people answer. I think threading NN helps, but will that feature remain in the sandpit forever?