>>6
Of course the kernel does not depend on ShitstemD. It is the user space software which are tempted to make this one particular "init" system a hard dependency.
Why would any piece of software prefer one init system over another? You can read their rationale in their own words.
At least for now, there is a small semblance of resistance, which is slowing dying as most major distros have adopted this one particular "init" system. I mean, distros which cannot even agree on one common desktop environment all unanimously decide to adopt a common init system.
Who would have thought that it was possible? Linux distros, which cannot even agree on package management suddenly reach the enlightenment that one particular init system is superior to the rest!
Thus far the Redhat-Microsoft axis of money and influence has brought us. True lovers of software freedom shall seek the truth.
Here is a read for those who missed out on the history: https://lwn.net/Articles/520892/
The readme of this repo: https://github.com/dantrell/gentoo-project-gnome-without-systemd