Partially we want to consider a reason why it might be made.
Like yeah, it's a dogshti trade and it's been proven to be.
But teams generally don't go out of their way to make shitty trades. GMs who built a Stanley Cup roster in their pasts generally don't go out of their way to make shitty trades. So any of the "justifying" or "defending" is trying to add context and understand why a bad move was made.
I'll stick with the thought that Yzerman figured he had Trouba in the can or Stammer was hot and heavy on joining Detroit and then it fell through because Trouba's wife nixed the deal and/or Nashville came and nuts on the table beat Stevie's 7-8M per for Stammer by a couple million. So a dogshit terrible move which was made for salary relief looks that much worse because you didn't use the salary relief for the big score you were hoping to.
So it was probably a confluence of events. And Walman proved any concerns about his being a teammate or bad voice in the locker room were overblown by slotting into SJ and playing really well. He definitely could have been a massive dick in Detroit that rubbed people the wrong way and got sent to a shitty team and realized "wow, I better shape up" and did so.
I'll end with the fact that Yzerman's original deal sending Walman and a 2nd to SJ was dogshit terrible but the fact that San Jose got a 1st for him the next year does not make Yzerman's deal worse than it already was.
Teams are allowed to be over the cap in the offseason. If Yzerman made a move to clear cap without having the follow-up move confirmed, that is also an indictment on him.
Incredible the number of excuses guys will make here for Steve. If Holland did these things we would have eaten him alive. Yet Yzerman has a group defending every single move as "not that bad" or "has context". No, sometimes the context is that these people are actually somewhat incompetent. It's not always that deep. There have been incompetent GMs before and there will be in the future. It's crazy to me to see the insistence that Yzerman's incompetent moves are because of some big-brain strategy instead of the most likely explanation - that he's just not a very good GM. He is my favorite player of all time but that has nothing at all to do with his executive career, and it seems many can't see that.
Yzerman has been bad. Full stop. I also tried to defend him on that main board thread many times, but you have to call a spade a spade at some point. We keep hearing from people that "good players don't want to come here", "what did you want him to do?", etc. Thats' the whole point of a GM's job. To find diamonds in the rough, draft well, trade well, and build the team into a contender. The only thing he's done well is draft, mostly at the top of the draft.
Everything else - trades, FA signings, waiver wire pickups, and especially pro scouting - he has been horrible at. We don't have to have the obvious answers in order to criticize the GM. If it was so f***ing easy that any dumbass sitting on their couch at home could do it, why are we paying Yzerman millions of dollars to do so? Just poll the fans.
The job is hard, sure, but that does not excuse lack of performance.
People will talk about not having a top 3 pick but that's entirely irrelevant TBH, since we got Raymond and Seider anyway, and they're top2-3 players from their drafts (as I said, drafting has been solid). Ed too. Problem is, that is not enough. Look at Jim Nill in Dallas. Bischel, Harley in the mid-1st. Hintz in the 2nd. Robertson in the 2nd. Johnston in the late 1st. The only high pick he's had is Heiskanen. Then he went and supplemented that with a phenomenal signing in Marchment. A great pickup in Duchene. Added Granlund. Or look at Colorado - got top picks in MacKinnon and Makar, but then supplemented heavily by scouting out and adding Nichuskin, adding Toews for incredible value, etc. That's how you build a team. Can't just expect the kids alone to take you to the next step.
This team is doomed for failure unless Yzerman actually makes some moves to try and improve us instead of hoping and praying Danielson et al will magically. fix all the problems.
Another good example of what I said above btw is Washington - Aliaksei Protas, now his brother looking amazing, and signing Prtoas to a phenomenal deal before he's broken out this season. Miro looking great. Buying low on Strome. Buying low on Dubois. That's what good pro scouting
in addition to good drafting looks like.