Fairy Tale Tangent

In reading Tolkien’s essay “On Fairy Stories,” I had a thought. He says that if man ever reached the point where he was not interested in truth anymore, then he would also lose interest in fairy tales, since the delight in such stories comes from the knowledge that we are subcreating. The story goes that some people felt depressed or suicidal when they saw Avatar, because the beauty wasn’t real. Is this a symptom of good fantasy, or the side-effect of a postmodern abandonment of truth?
Good fairy tales allow you to enjoy the juxtaposition of our creation with God’s. Do bad ones make us hate the real world and long for the story? I think so. In that case, I would submit that the story has ceased to be a story and has become a lie. The beauty of fairy tales rests in God’s good world, not apart from it.