That is because the Teams in the west are playing more teams against each other. That means "decent" teams in the west beat up on the super weak teams over there and pad the stats.
I didnt realize that the schedule was so conference heavy until this post made me look at my schedule. My team only plays the west 24 times out of 82 games. So that means I play the tough conference 58 times giving me lower overall point totals then a team playing the weaker teams 58 times.
That is my theory, and I am sticking to it!