Fedora keeps sendmail — for now

You did give the impression that »Lennartix« was supposed to be an operating system that could no longer be maintained with »simple Unix file tools«.

One can probably quibble about whether journald's binary logs are A Good Thing (as of now it's not as if journald was mandatory in any way, shape, or form, even on systemd-based systems, or would preclude the use of a traditional syslog daemon). However, I don't think it is quite fair to suggest, even ironically, that Lennart Poettering was against text files for configuration – if anything, systemd itself is an obvious counterexample to this claim. Quite on the contrary, systemd is probably doing more for the cross-distribution standardisation, and hence future-proofing, of these text files than any other effort has done recently.

As far as binary configuration goes, there are various systems that try to store Linux configuration data in an LDAP directory, which is probably the closest we get to a »binary registry« these days. Like you said, there are some advantages to this (especially in larger networks) but so far nobody seems to be advocating for making this approach standard.