Authority

I think it was a good thing that Linus announced that he intends to improve his "conduct", even though in reality, and especially in recent years, it has rarely been a problem (most of those pointing out his "poor conduct" keep repeating the same handful of cases - most of them years old).

However saying "I've been rude in the past, sorry, and will improve now" is one thing, as it only *directly* concerns Linus himself, though hopefully it will have beneficial trickle down effects.
Whereas introducing a CoC that creates new rules and responsibilities (especially for maintainers) and raises a lot of issues is quite a different thing.
That it was done in a rush, without discussion, apparently even among maintainers who are the most impacted, seems very strange and contrary to the way the kernel development process normally works.

Especially as the kernel *already* had a CoC, in the form of the "code of conflict".
Normally when some old code is removed and replaced by something else there is always an explanation in the changelog of *why* it was done.

Of course Linus *can* commit anything he likes to his tree but that's not the way things normally work so I think it's quite normal that people are surprised and a little concerned when that happens.