A big part of that 20 year run was luck
The only reason they remained on top in the mid-late 2000's and into today (Though they aren't the cup contenders they once were) was because they got lucky with Datsyuk and Zetterberg. In the mid-late 90's the Devils, Avs and Stars were just as well run, drafted just as well and just as successful at the Red Wings, but those teams didn't get as lucky so they've all had to go through down and rebuilding phases while the Red Wings remained on top.
Both Datsyuk and Zetterberg only played 45 games last season, as they both missed half the year with injuries and the Wings still made the playoffs.... Do you think the Leafs would be sniffing the playoffs with Kessel and JVR both gone for half a season? LOL The Leafs can't even sniff the playoffs with both star players in the line up. Detroit is a very deep team. Its not just Z and Pav carrying that team anymore. Z and Pav are two of the very best 2-way players in the game and they don't even kill penalties for Detroit any longer.
Were they lucky to get Z and Pav? Sure, any club would be lucky to get them. But at what point do you acknowledge that it isn't just luck, how they manage to find elite players that others routinely pass on? They seem to be able to find players in the draft that turn out far above popular projections.... Lidstrom, Homer, Z, Pav, now Nyquist, Tatar, Sheahan, etc...
JVR 25yo 21G 2nd overall pick $4.25M
Kessel 27 yo 19G 5th overall pick $8.0M
combined 40G (-30) on season at a cost of $12.25M in cap space
Tatar 24yo 21G 60th pick $2.75M
Nyquist 25yo 19G 121st pick $950K
combined 40G (+3) on season at a cost of $3.7M in cap space
Detroit is just a well run hockey club, I don't think luck has a lot to do with it.