I think we are at fault here more than Pogba, He is never a player that take everything on his shoulders and drag his team out of trouble.
He is a kind of player excel if we given him freedom by playing 2 solid centre midfielders like Juve did when he was there.
At UTD he never has that kind of luxury hence he is not enjoying playing for us. Few best games were when he had Herrera next to him so you can imagine what we need for Pogba to be a success, On top of that Media and fans are hounding him for not delivering on his own.
Judging his nature, Juve move would suit him because if things dont click at Madrid, their fans will be come down pretty bad on him.