Let's hear your argument.
The only team to get significantly worse on that list is the Islanders. But, they still have a young team, and more depth than Detroit. Every other team either stayed the same as they were last season, or have improved. Detroit on the other hand has a goalie made of glass that both played the most games he's played since his 20s and posted his worse numbers in over half a decade. They also lost their #1 center, while having very little center depth to begin with. Finally the defense is aging like milk with no significant moves toward improving it. So there is no reason to believe the defense will be any better next season, there is no reason to believe the centers will be better, and no reason to think the goalies will be better. So that means Detroit, even if everyone stays about where they were, only treads water. If there is any drop in performances by Green (who by every measure had one of his worst seasons last season, and is on a downward trend), Howard (who also had one of his worst seasons last season), Kronwall (who is barely able to play), Nielsen (who is had a horrible season, and is trending downward), Ericsson (who is oft injured, and also is trending downward), Daley (who again, is trending downwards), etc. then Detroit doesn't just tread water, but continues to sink. And I only named players at premium positions. Detroit needs, somehow, for those players to stay right where they are at, while not only replacing Zetterbergs missing ~60 points, leadership, and defense, but also collectively exceed that. So, if what's likely to occurs, occurs, that is that most of the listed players continue to see their ability to play at a high level drop, their totals drop, and the young kids either stay the same (likely with Larkin) only have predictable, modest increases in output (Mantha), there is no way Detroit is even as good as it was at the end of the season last year.