The point isn't that Penn State can't do it. The point is that on a cost-benefit basis, the benefits of practicing a completely different formation (better short yardage and QB sneak potential) are outweighed by the cost (more turnovers from snap problems).
And maybe the the biggest cost is opportunity cost. Would you rather the Penn State offense devote 50% of its practice time to learning the I formation, of would you rather they maximize development of the offense they run now; i.e. a more diverse array of passes and more sophisticated running with more misdirection. I think this offense is on the right track and I want them to stay on track. They have just begin to show the ability to do power running. If they can add medium and deep passing, and more screens and flat passes to the backs, that would have a lot more impact than being able to do QB sneaks.