Why don't you start with trades where he's "always extracted solid value" as you've made in your claim?
1. Traded Kadri for Barrie and Kerfoot -> Kadri goes on to win Cup
2. Traded Marchment before he broke out
3. Traded Connor Brown before he broke out
4. Traded Barabanov before he broke out (are you noticing a trend here?)
5. Traded a 1st+two 4ths for Nick Foligno in the year 2021
6. Traded a 1st+2nd for an over-the-ropes $10million dollar Erik Karlsson (to a team that already has Kris Letang)
7. Traded the most valuable Penguins trade piece in 20 years for a 2nd round pick and a $4.5 million Michael Bunting
That's off the top of my head but I'll allow any of those disgruntled Leafs fans that always trickle into these threads to help me out here and add more.
Your missing some of his classics and some of the sweet returns on a few of the deals you mentioned.
1. Traded Patrick Marleau, a 1st round pick (Seth Jarvis) and a 7th round pick for a 6th round pick
2. Traded Trevor Moore and two 3rd round picks for Jack Campbell and Kyle Clifford.
3. Traded Mason Marchment for Denis Malgin.
4. Traded two second round picks and a 3rd round pick for the corpse of Mark Giordano.
5. Traded Petr Mrazek and a 1st round pick for a 2nd round pick.
6. Acquired Matt Murray and only got a 3rd round pick and a 7th round pick as the sweetener.
7. Traded a 1st round pick, a 2nd round pick, a 3rd round pick, Adam Gaudette and Mikhail Abarmov for 24 games of Ryan O'Reilly and 23 games of Noel Accari.
With the Penguins, the Karlsson trade was dim-witted at best, and I can't fathom why he takes on contracts, like Rielly Smith and Kevin Hayes without being compensated much better than he has. How he managed to trade Jake Guentzel and somehow not receive a 1st round pick back was absolutely baffling.
I think he's the worst General Manager in the NHL and his inability to make a trade without getting bent over his desk is a huge part of the issue.
I get why he would be gun-shy of making trades because of how bad he is at, but another huge issue with him was all of the talent that he just had walk away during his time in Toronto because he somehow thought his team was a cup contender so he didn't trade away expiring contracts and he bungled the swap so badly he couldn't re-sign the players.
Guys that had actual value who simply left as free agents like Jake Gardiner, James Van Riemsdyk, Tyson Barrie, Fredrik Andersen, Alex Kerfoot, Zach Hyman, Ryan O'Reilly, Nick Foligno decimated their depth, and then his free agent "replacements" were so bad, he would then have take a loss just to trade them away (like trading Petr Mrazek and a 1st to cleverly acquire a 2nd, or trading Nik Ritchie and a 2nd round pick for 38 games of Ilya Lybushkin, and having to take on Ryan Dzingel, too.
Much has been said about his, shall we say, generous negotiating ability when it comes to free agency, but what is equally hilarious when it comes to free agents is some of the choices he makes. Imagine having a young team that is brimming with talent, but just can't get it done in the playoffs and you want to change the culture of the room and bring in a veteran that knows how to win.. So you sign... Joe Thornton?
He's just a terrible, terrible General Manager.