Ya no idea what SY was thinking on that one.
21g, 53pts(18pts in 16 games after the deadline deal) in 21-22. On pace for another 20+g, 55pts season the previous year. Plus another 14pts in 20 playoff games for a 3rd rd Rangers team in 2022, and 28 years old. That's why he got $5.5, if you go by the rule of thumb where every 10pts is worth $1m on the cap.
While owners will win in CBA negotiations, wanted players win in individual negotiations.
It's easy to not be in the game and say this or that contract is stupid. Most of the time, you're right. I would bet even the GMs know that the contracts they offer, many of them are stupid, and will not age well. However, their job is to acquire talent and win. If a GM hands out a 6 year deal to a UFA, he's hoping to get 2 good years out of it. Maybe 3, if he's good. If too many contracts fail, he's fired, and the mess is someone else's problem. You can only get who is available though. Are there better players than Copp for whatever role the Wings got him for? Probably. Could you get them as easily as you could Copp? Probably not. So you roll the dice with who you got, and Copp has not been worth the contract for even a year yet, and he's likely passed the two best years he was going to have.
The point is, you can never truly trust players. Either to show up on any given night, or not check out after they get paid. Same reason coaches do "stupid" things, as their fate, along with a GM's, is tied to player performance. You can't trade 20 players, as the saying goes.