[avar]

I think it's legitimate to complain about systemd not being portable, but it's odd to do so in terms of the non-portability not being "simple".

Imagine how much more complex systemd would be for even common things like "start this daemon and make sure neither it or any of its sub-processes collectively use more than 1GB of memory" would be if it had to run on z/OS, AIX, Solaris, OpenBSD, HP/UX, Windows, Mac OS X etc.

And let's be clear, systemd is perfectly usable for things that don't want to depend on glibc, for example it works just fine for starting Go programs, or your random C program you've linked to uClibc. What you can't do is not have a glibc on your system at all. Given how tiny glibc is in terms of modern hardware resources, if you can't have it on your system you probably weren't the target audience for systemd in the first place.