@Mirage Care to explain this then?: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/init/main.c#n1491

Linux is not a Unix kernel, as it doesn't contain any code from Unix kernels.

There are a few Unix-like OS's, but very few of them are actually Unix's (GNU's Not Unix is the name of the GNU project for a reason).

Yes, you can use another init than systemd, but I'm pointing of that Linux is only a kernel and not an OS, as it doesn't *operate* on its own.