@hippie_genocide: It kind of comes down to the "best player on the best team argument." Harden's keeping Houston in contention, but Curry's playing a big part in keeping the Warriors on top all season. I don't think Curry should be penalized, either. He makes his better teammates even better.
Another thing is defense. Golden State's D is tops and Curry's been improving on that side. He's up there in steals and is far more than just a scorer.
(yeah, that's last season, I know)