I don’t doubt that people on all sides have made mis-steps, but from the outside it mostly just seems like Kent doesn’t want to play by the rules (despite having been given years of patience).
IMHO, what his communications show is an unwillingness to acknowledge that other projects that include his work have focus, priorities, and policies that are not the same as that of his project. Also, expecting exceptions to be made for his case, since exceptions have been made in other cases.
Again IMHO, I think he would be better off developing apart with an announcement mailing list. When urgent changes are made, send to the announcement list. Let other interested parties sort out the process of getting those changes into the kernel and distributions.
If people come with bug reports from old versions distributed by others, let them know how to get the most up to date version from his repository, and maybe gently poke the distributors.
Yes, that means users will have older versions and not get fixes immediately. But what he's doing isn't working to get fixes to users immediately either.