That's because systemd originated at RedHat. If it had been designed distribution agnostic it would have worked a lot better on other distros besides RH.
What are the non-distribution agnostic parts of systemd? Considering it runs as PID1 (usually) it kinda is the base of distros and not really built on top of any distro other than "the linux kernel".
What are the non-distribution agnostic parts of systemd? Considering it runs as PID1 (usually) it kinda is the base of distros and not really built on top of any distro other than "the linux kernel".