Ah...while I definitely want to limit answers to the topic question, I think I can parse it down a bit. While I don't see it much, I find no problem with artists labeled "Christian" doing songs about the general topics of life. In fact, it should happen much more often than it seems to.
My question arises from the discussion of the song "Awesome God". Setting personal taste aside, what should a worship song/song about Christ sound like?