They're literally coaching the offense out of him in the name of "defensive responsibility". A man can do both.
As an aside, this is why I've always balked when people keep saying they want to see Z develop as a center. I don't think that's a good use of his abilities. He's such an offensive dynamo when he's mostly freed from big defensive responsibilities that any offensive-minded coach would have penciled him to a winger role and gotten a more defensively responsible center for him just to allow him to shine doing what he's the best at.