He was moved mainly because Yzerman was trying to get Trouba. And he was the only dman with any value on the team outside of Ed/Mo. SJ probably wanted to wait and Yzerman wanted to get it done quickly so he added the 2nd. Then Trouba falls through and the team is left with this... He did not shop him around, and he had no interest in trying to "fix" his game in Detroit. He's an extremely stubborn GM, and that's how you end up with moves like this
* Rangers GM calls Yzerman -
"Steve, I want to move Trouba and I doubt he would put his hometown Detroit team on his no trade, but we have to move quick, you have 1 hr."
Steve "OK, just need to open up some cap space"
*Steve calls Sharks GM -
"Mike, I need to open some cap, take Jake Walman."
"No"
Yzerman panicking"Please, I don't have time to shop him around, I will thrown in a second rounder?"
"Fine" Sharks GM starts laughing after hanging up.
* Yzerman calls Rangers GM back up -
" OK, ready to do the Trouba trade"
Rangers GM "Sorry, Jacob got wind of the deal and put Detroit on his no trade list, no deal"
Yzerman hangs up phone and openly weeps.