They should also be considering that many shops that otherwise might want to use famfs won't because they have security concerns about the eBPF subsystem in Linux.

I'm also having a problem with the gatekeeping and moving goal posts going on in with the kernel maintainers. There are Arm architecture maintainers on record *refusing* to allow merging of ARM64 CPU features that enable more performant AMD64 emulation as if the kernel is their pet project and not the efforts of thousands and at the service of many millions. The shifting goal posts for famfs is just evidence of more of the same. It's one thing when projects refuse to play by the rules. It's quite another when outsiders engage in good faith then repeatedly get shot down because multiple people have too much veto power in personal fifedoms. You end up like the Polish government back in the day where nothing could get done that didn't cater to the most powerful of the barons who could marshal or browbeat the others from using their veto or just did what they wanted to because no one else could marshal an objection to fait accompli.

Has anyone done an analysis of how many lines of patches that go into the various distro maintained kernels that aren't/won't get upstreamed, and how many were refused by 'official' subsystem maintainers? Sometimes they do have legit reasons to block some patch sets, but the real question is how many were blocked for specious reasons like the Arm compatibility patches were.