I would imagine that the players base their vote on respect for certain individuals. For example... Would MLB pitchers vote for Trout or Cabrerra? My guess is they would vote for the guy they least want to face at the plate in a crucial situation. Seeing that MLB pitchers account for about half the rosters they pretty much as a group decide the results.
Mike Trout's numbers might be better overall, but would MLB pitchers rather throw to Trout or Cabrerra? Who do you think they would rather have at the plate? I doubt they consider defense and base stealing all that much when they are asked this question. I doubt if they considered it much when they voted.
I have to agree with JH regarding the writers... or at least most of the writers. I was pulling for Mike Trout, but I'm fine with Cabrerra being the MVP. He had a great year!
One advantage Cabrerra had was that his own teammates really pumped him up as the best player in the game and the MVP. I don't recall that happening with Trout and the Angels or maybe I missed it. When people like Velrlander are calling Cabrerra the best player in baseball, I imagine it has an impact on the voting. Then you add the triple crown, first time in how long?