We invoke sethostname() from inside systemd since that is one of the
most trivial system calls known to men and doing this with a
separate
binary is just absurd. This way we also can ensure that the hostname
is
always initialised which is very useful for early boot logging and
other
stuff. On systemd you get the guarantee that the hostname is always
set
up if you run in userspace,
You can't possibly know what kind of (possibly dynamic) hostname
admin might want to assign to his machine. The static hostname
may be as useless as default "(none)" which is set by kernel.
Anyway, logging with default hostname is not a catastrophe.
Why do you set up stuff no one asked you to?