No arguments there, I'm more talking what that means for the "build and distribute your own dev/rpm" part that follows. Why are the only options "do work for maintainers" or "provide a prebuilt package for the distro", what happened to "nobody said this needed to be done yet"?

No problem, if upstream doesn't want their software packaged for Distro X, nobody needs to do anything.

The thing about Linux filesystems, though, is that they consist of two parts: the kernel patch and the userspace tooling. Bcachefs is already in the kernel, so it's a bit awkward to leave out bcachefs-tools. Which is probably why it got packaged in the first place. Stable distros generally don't want loose ends flailing about in such a critical part of their system. If nobody wants to maintain bcachefs-tools for Debian, Debian will probably remove bcachefs entirely from their kernel as well.