He represents the "pulp fiction" version of the west and has to be educated about the reality.
Although he's a complete weasel, Beauchamp can at least be applauded for possessing some small amount of intellectual courage. Once his initial ideas about the Wild West are completely exploded during a conversation with Little Bill, it would have been easy for a lesser man to leave and forget the whole thing.
But Beauchamp at least decides to stick around Big Whiskey, and learn about the reality of the frontier. In a way, then, he does commit himself to trying to get it right, even though he seems to idolize Little Bill a little too much at times.
