It's not just a story about a guy who's trying to defraud the world. It was the humanizing effect of seeing Ravenshead through the eyes of a loving wife that cemented Eckert's interest in the material. He's a gentle soul. Eckert's wife, the actress and playwright Ellen McLaughlin, gives voice to the unseen Mrs. Ravenshead. Her delicate, loving voice hovers above the action at several crucial points, making the story something more than a portrait of madness.
Flawed logic is interesting.
There is a larger body of flawed logic surrounding Ravenshead. By changing the English Crowhurst into the American Ravenshead, Eckert and Mackey altered the more British theme of the failure of empire. From the American standpoint, this is the hubris of imperialism, which is a different thing. Hubris is less pathetic. There's a dangerous side to it.