Because this isn't a case of a codes of conduct being universally bad, but rather a case of one instance of it being bad. A GOOD code of conduct will be specific and lay out what is acceptable without vagueness.
Except it wasn't harassment -- guess what? People can say you're wrong. Check your ego at the door if you give a public talk. They shouldn't say "he's a fucking idiot" but saying "I feel that got X,Y, and Z wrong and here's why:" is not a fucking CoC violation. I support codes of conduct and always will but this is where things went topsy-turvy, do not try to roll your own and try to be specific.
I support codes of conduct but this is EXACTLY the thing that opponents point to when they oppose them. I expected this post to be a rant against codes of conduct and instead it wound up leaving me wondering if NumFOCUS and JupyterCon was in the wrong here...this guy offered criticism and that is NOT a fucking violation of ANY CoC -- if you can't handle criticism, don't make public statements. The hilarious is that Joel Grus didn't care -- like what the hell...this is why sometimes I feel like proponents of CoCs are at times their own worst enemy when it comes to attaining wide support for them.
Location: New York, NY (open to Jersey City/Hoboken)
Remote: yes
Willing to relocate: NO
Technologies: Ansible, Docker, Python, Ruby (Mostly looking for devops-ish side of things), learning AWS and can find my way around with documentation.
You do realize that bad habits tend to not die, right? Don't teach bad practices because you're targeting newbies...teach them the best practices from the start.