In the orginal story, he was a weakling schoolteacher. In Burton's version, he is a detective who is intent on using scientific methods to solve cases. He abhors the barbarity of the methods used at the time. This sets him up as more of a skeptic due to his scientific mindset than just because he's an outsider. It also allows Burton to work in a backstory which helps flesh out the character of Ichabod, and gives the reason for his rational, scientific mindset. In both, he was an outsider who originally doubted the truth of the stories.