How, exactly? The CoC does nothing but codify someone's values for a community. It doesn't actually do anything, other than state a set of unacceptable behaviors and potential solutions to those behaviors. It's still up to the contributors to actually act, and if your community is good in the first place, they won't need the prompting of a CoC to act against jerks.
> How do you imagine this happening?
Easily - a CoC leaves a lot of grey areas, which provide plenty of room for griefing and harassment which isn't technically against the CoC. And if an action falls within that grey area, someone, or several someones, has to take time and not just say "this is bad", they have to tie that judgement back into the CoC somehow. It's even worse when there are consequences in the CoC for "lack of enforcement of the CoC" - being perceived as doing nothing can remove someone as a contributor. It's worth remembering, we're (mostly) developers, not lawyers.
> Except the people doing it are complaining about not being allowed to be jerks.
Are most of the people in this thread of comments complaining about not being able to harass or abuse other people? Or are they raising concerns about the ambiguous nature of these CoCs, and the perceived unnecessity? More specifically, how much time did Matz have to take out of his development schedule just to address the complaints against Ruby's CoC?