It's helpful when people are being assholes to point to a document describing how they're being an asshole and to cut it out
Is it really? In this example, could you not see anything wrong with calling employees losers and monkeys, until someone linked you the CoC?
In my experience it's the opposite of helpful, because it's actually a lot easier to reach consensus on whether someone's being an asshole than on whether they have violated the code in the document.