The more and more time passes and I ponder this situation, the more I realize that DA never had any intention to sign Pietrangelo.
The Blues win the cup, Pietrangelo wants to start talking about an extension. DA promptly suggests they wait.
Just before the season, he acquires and extends Faulk to ensure he's here for 8 years. He is paying a premium for a player that plays the same position as Alex Pietrangelo. Why? Who knows, Faulk had been regressing for years.
Faulk, as anyone who did their research might expect, struggles mightily. One, because he's been declining for 3 years. Two, because the only way he produces is by being spoon-fed PP minutes, which, he couldn't even maintain on the Blues because they had three better options. Furthermore, all statistical models project his contract as one of the bottom five contracts in the league. Will Seattle, a team with a massive analytics department, just pluck him without the Blues paying a high price? I don't buy it.
On top of that, he allocates significant cap to Schenn & Scandella. One player who has also been declining for three years, and a replacement level defensemen.
So now we reach negotiations. DA isn't completely null and void of logic. He knows, a defensemen of Pietrangelo's caliber is going to demand signing bonuses and movement control. He low-balled, offered a partial NMC in the later years, and minimal signing bonuses. So naturally, Pietrangelo walks. When he walks, he gets exactly what he demanded, which was fair and deserved, because he's an elite defensemen.
DA then rushed and panicked to sign Krug. Krug, like Faulk, requires significant PP minutes to have any success because his 5on5 play can be described as mediocre at best. Krug, like Faulk, has now been declining in performance for a few seasons. Krug, also requires significant sheltering to not be liable. Is Krug better than Faulk? Certainly. But is the gap between Faulk and Krug smaller than the gap between Krug and Petro? Absolutely.
People often point to the 'what if DA knew Petro wouldn't sign and that's why he got Faulk.' But, one, that doesn't justify making a terrible trade for a meh player and signing him to a huge contract. Two, have you not considered that DA had no intention of signing Petro to begin with? He certainly had no intention of it before the 2019-20 season started, based on the evidence.
I wouldn't lambast DA if he made a rather astute trade and brought in young, relatively cheap talent to fill the need on D, with the potential to develop into a legit player, while promoting Parayko to the #1D spot. Then the argument of not wanting players into their late 30's on expensive contracts is well followed.
Instead, two PP specialists into their late 30's? Marco Scandella for 4 years? Schenn, who plays a physical game, for 8 years?
Just seems like, for whatever reason, they didn't want Petro apart of the organization going forward.