My premise would be that they built up a pretty deep team in terms of assets but mortgaged the future for that one cup in 1994. If you look at all the mismanagement during that year and beyond, it parallels to what WCW did when they were beating WWF.
There's stuff that helped them win the cup (in theory) like trading Tony Amonte for Stephane Matteau and Brian Noonan. Doug Weight for Esa Tikkanen. To a lesser extent, Todd Marchant for Craig MacTavish and Mike Gartner for Glenn Anderson. They should have been able to build a team that won consistently.
After the Cup win, they kept doing trades to acquire "big names" and signing big names. They traded Sergei Zubov and Petr Nedved for Robitaille & Samuelsson. Zubov was 25! It's bad enough when you focus on the trades they did make without going into the ones that they didn't make, like being unwilling to part with Manny Malhotra in order to get Pavel Bure from Vancouver.
Bringing in Gretzky propped up this terrible strategy for a year because Gretz had that underrated playoffs in 1997. Bringing in Gretz might be like WCW bringing in Bret Hart, getting that one great buyrate out of him then wasting away his last few years.