Perhaps a bit too scandalous (I don't know), but my understanding is that there was also a falling out of sorts between the DragonFly lead and BSD people, large

Perhaps a bit too scandalous (I don't know), but my understanding is that there was also a falling out of sorts between the DragonFly lead and BSD people, largely caused by allegedly abusive behaviour form the DragonFly lead while they were still working on BSD main. As I understand it, DragonFly came after this. Maybe doesn't answer your question, but it contextualises (however accurately!) part of how it came to be. My source on that is a LinuxConfAU talk I can't recall off the top of my head (the same speaker gave a somewhat notable talk in defence of SystemD)