Melville's Indifferent Characters

While reading Benito Cereno, I was struck with how much Delano reminded me of of the narrator in Bartleby. The lawyer in Bartleby tolerates his employees shortcomings, specifically Bartleby's refusal to work, for most of the story, which was very aggravating as a reader. Even more frustrating, however, was Delano's continuous dismissal of his suspicions of Cereno and Babo's relationship and of the ship's crew in general. While Bartleby's lack of work ethic was annoying, the eery and unexplained history of the San Dominick becomes life-threatening for Delano, therefore his distract-ability and disregard for suspicion was all the more irritating to read even before I understood the history of the ship and its crew myself. I wonder why Melville created two central characters that are so indifferent and unassuming. I feel like these qualities would get them into more trouble than it actually does, but miraculously both the lawyer and Delano remain safe from the troubling characters the interact with.