You point to a case where someone was freely able to harass and abuse other members of the community for years as an example of why CoC's aren't needed?

You accept that you need to exclude people for the health of the community but you continue to reject CoCs because....you once were involved in a board with someone that took a long time to establish one?

I personally think a lot of the push back is from jerks fearing that they will be pushed out of the only communities that have dealt with them up to now.

There are stereotypes about programmers and their social skills and if over 20 years programming has taught me anything it is that they portray way too many individuals involved in it accurately. A lot of people do need to be told exactly what is or isn't appropriate. A lot of people do need something like a CoC to feel comfortable reporting abuse.