I've said it elsewhere: management sets the tone, not the code of conduct. If there is a random arsehole behaving badly, they get ejected, with or without code of conduct. But is a person of power behaves like an arsehole, then it's up to management to decide if proper behaviour is mandatory or optional.

My feeling is that codes of conduct mainly serve the salesmen and workshop providers. The thankfully defunct Ada Initiative was the worst actor, but others have stepped in.