Some argue that now that Linus realized how his communication is received sometimes, he will suddenly not be able anymore to tell people when shitty code is shitty. There are a billion ways to tell somebody their code is shitty with out attacking the person themselves, some of which might even make them realize that you are right. And Linus certainly didn't sound like he doesn't care about the kernel anymore.
IMO the Code of Conduct has nothing irrational or outrageous in it:
* don't be sexist (you can critique someones code without making it about their gender or gender identity)
* don't be racist (you can critique someones code without making it about their race or origin)
* don't be shitty to people who know less (you can critique someones code without making them about them beeing a noob, and help them getting better)
etc.
I don't see how having more harassment would aid code quality.