Maybe because people are tired to see another MVP award to Westbrook, with this line up, he will be limited with minutes and I don't think he can do what he did in the past all star. Maybe this time, if the East will win, we will see James Harden as MVP. I'm sure this guy is hungry for that award and will do his best to get it and win the team.
I have a trivia for you:
Didn't you know that Russel Westbrook is the All-Star MVP during 2015 NBA All-Star game. He is not part of the starter lineup back then.
See? Even with limited minuted he grab the MVP title. That is really depend on a player if he will play aggressiveness and forget about entertainment purposes. Well All-Star MVP title is a good achievement too while you are having Season MVP and Finals MVP title too but unfortunately for Westbrook, still a long way to reached that status.