In the first movie, we see things mostly from Starling's "sane" perspective, so it's fitting the tone of the movie is gritty and realistic. But the next movie the story is really Hannibal's. And instead of confined in a dungeon wearing jumpsuit, he is living the way he wanted. Here is a guy who scorned all social taboos, who listen to Goldberg Variations while beating a man to pulp and quotes Florentine history as he disembowel a victim, not to mention his dietary inclinations. He is an over-the-top, larger than life individual. So a story focused on Hannibal on the outside necessarily become over-the-top.