He is helping his team win in a ridiculously efficient way:
http://www.cougarboard.com/board/message.html?id=13770038
If there were a POY award given without regard for wins and losses, I would vote for Westbrook because of his triple-double prowess and the insane numbers he is putting up.
But, to put things in perspective, KD won the MVP award last year, largely because he led his team to a second place finish in the west (winning 72% of their games). He had to carry the team, because the second best player on the team (Westbrook) was injured for large stretches of the season.
http://espn.go.com/nba/standings/_/year/2014
This year, the roles have flipped, and Westbrook is having to carry the load with Durrant injured for large stretches of the season. The difference is, this year they are fighting for their lives to even make the playoffs (winning 56% of their games).
http://espn.go.com/nba/standings
Steve Nash won back to back MVP's because of his teams success and his proficiency (one of his MVP years he was a 50/40/90 guy if I recall correctly). Some would argue that Kobe was more deserving during one or both of those years ... but the Suns were more successful as a team, and Nash was the catalyst.
Now Curry's numbers are ridiculous - both offensively and defensively ... PLUS, his team is winning in a big way right now. Therefore, he gets my vote.