I think people assume the Hippocratic oath actually makes a difference. It's culturally important to many doctors of course, but how often has that hindered the military or the CIA from hiring enough doctors to facilitate a new interrogation program? Of the illegal human experiments that happened in the US many had doctors working for them as well. It's a good guiding principle but the idea that it would actually make an impact of any kind is debateable. It doesn't matter if 90% of coders follow the oath if 10% or even 5% are enough to handle the demand for oath breaking.