Mel Gibson's Sacramental Imagination

On Good Friday I was able to watch The Passion of the Christ for the first time in several years and the sacramental and Marian qualities of the film made an extraordinary impression on me. Gibson's Catholic vision is what makes the movie so compelling to me; his sacramental imagination, reliance on tradition, and reverence for the role of Mary all add to The Passion's distinct power. Without these aspects, The Passion would have been impoverished. I haven't seen Nativity Story, but it would be interesting to contrast the power of Gibson's vision with the Nativity Story, which, from the accounts I've heard, was slightly insipid. The general reaction of most Catholics to the Nativity Story was that there was nothing specifically "objectionable" in the portrayal; layered conspicuously into this comment is a sense of deflated expectations, of not living up to the high standards set by The Passion. Why did Nativity Story, an intrinsically compelling story, leave most of its audience feeling disappointed? If anyone can illuminate this question for me, please don't hesitate.