What was the baseline of his character, standards, and motivations drawn by the film? He wasn't that interesting, and what flaws he exhibited were minor and overcome and forgiven with a snap of the writers' fingers.
In real life, his first show was an awful exploitation of an old slave woman, but later in life he was pro-abolition. He also made money perpetrating hoaxes and frauds but later apparently became something of a debunker. I know very little of him, but he sounds much more interesting than was portrayed, warts and all.