The argument on Trout’s behalf isn’t all that complicated: he provided the greater overall contribution to his team. Trout was a much better defensive player than Cabrera, and a much better base runner. And if Cabrera was the superior hitter, it wasn’t by nearly as much as the triple crown statistics might suggest.
Trout, with his speed, aggressiveness and good judgment on the bases, was also able to help the Angels in other ways, such as by scoring more often from second base when one of his teammates got a base hit. With the more detailed data available on everything that happens on the field, it is now possible to quantify these contributions as well.
Over all, Trout contributed about 12 additional runs on the basepaths when compared with an average runner. The bulky Cabrera, by contrast, cost the Tigers about three runs on the bases.
According to this measure, Trout was actually slightly more valuable than Cabrera as an offensive player, considering the timing of his contributions. Add in his defense and base running, and it isn’t all that close a call.
I don't have much to add. Silver knows his stuff and writes well. But in retrospect he seems a bit too optimistic about the voters. They gave Cabrera the MVP by a pretty good margin. While the media and older baseball people seem more open to stats, they still love the narratives they create. And apparently the triple crown narrative was too irresistible.
That narrative which places so much value on 3 specific stats shows how stuck in the old way of thinking they still are. The 3 stats are average, home runs and runs batted in. Batting average is only part of the story, which is discussed in Moneyball. If you want a triple crown type narrative, it'd be better to use on base % or slugging %. But they still use batting average simply because it's the tradition. HRs is a good indicator of a good hitter. But it's incomplete and as Silver points out, the number alone doesn't take into account park effects. RBIs are very contextually dependent. Driving in runs is certainly important. But RBI rate would be a better indicator of player effectiveness.
These narratives are everywhere in the media, sports and political. Hopefully, with the emergence of people like Nate Silver, they will fade out and more rigorous analysis will become more prominent.