Detroit is favored because
1. They've done this before
2. We haven't, collectively or individually (a couple bench players aside)
That's all there is to it - everything else the media is citing is just circumstantial. The fact that we've struggled in the playoffs and they haven't just strengthens the viewpoint that the Pistons are more likely to get it done, but we've gotta realize that all along, we weren't going to be favored against established teams, because, well, they're established teams.
Luckily, the media doesn't get to score, defend, or blow the whistle, so this is all water under the bridge, whether they're right or wrong.