I recognize that not everyone recommending codes of conduct literally comes from human resources, but it's the simplest way I can understand why somebody would

I recognize that not everyone recommending codes of conduct literally comes from human resources, but it's the simplest way I can understand why somebody would say "what this project needs is a document defining good and bad behavior." Perhaps it's just a personal hang-up. I believe some style guides are worthwhile, and style guides could be described as documents describing good and bad design or good and bad code.