I agree 1000%. The whole reason why the Wildcat offense became so effective at Arkansas and Miami is because they were using guys who were not only used to running the football but could also throw the ball fairly well. It seems like more and more teams who try to run the offense are getting away from that, thus making it less effective. It's not that defenses have "figured it out" as much as it's because many teams aren't even attempting to throw the ball out of the formation.