In the world of sports, teams are always trading players to try to improve there team. Taylor Hall should have been traded to improve his contract as well as make both teams better. Every trade can be looked at as a positive trade for every team because the team that normally isn't getting the better player will have more salary space available.
Media pundits are hailing the trade as a win for the Devils. It sounds like Hall would prefer to stay in Edmonton, and it certainly sounds like the Edmonton fans and media aren't happy with the trade. The overall thought is that the Devils are getting a good skater and solid scorer and Oilers may have cost themselves a shot at the cup.
Trading players is part of any competitive sport, in any country in the Western World. Hall was traded as many players before him have been and many after him will. He has some say, the companies both have a say; they are the ones who make this decision, for many reasons more than fans and commenters could ever understand.
Hall isn’t a consistently strong defensive player. Few Oilers wingers have made more mistakes that have led to more scoring chances against than Hall, and that’s saying a lot on a defensively mediocre team like the Oilers have been. Hall’s best scoring years may well be behind him. His leadership has been called into question.