i think the "unsustainable wild west" of sending sigterm, waiting and sending sighup was very good because it was adaptable (you were on your own if you had non standard stuff, but at least you could expect a contract)

Nowadays if you start anything more serious from your user session (e.g. start a qemu vm from your user shell) it will get SIGHUP asap on shutdown, because systemd doesn't care about non service pids. but oh well.

...which is where the jokes about "systemd is good for really fast reboots" came from mostly.