I think the triple crown is kind of a cute stat, like the cycle, but the argument for Cabrera is that he's been - by a good margin - the best player in the batter's box in either league this year, and he unselfishly moved back to third base (losing a fair amount of weight to do it) without complaining openly and played adequately there.
The argument for Trout is that he has been the second-most-valuable offensive player in the major leagues even if you disregard his defense [link
]. Even if you're skeptical about advanced defensive metrics - as am I - it's obvious that he's been a standout defensive player.
These are both very special players.