Why, though? Which problems do you see with systemd that can't be applied in the exact same way to the Linux kernel as well?

Some replies in advance:

It's monolithic -> Linux, but also, it isn't really
It's against the UNIX philosophy -> no, it isn't, and also -> Linux
It's against choice -> GNU/Linux is not about choice (see http://www.redhat.com/archives/fedor.../msg00861.html)
It's really big -> Linux; if space is your concern, you might want to look for another kernel which isn't enormous, maybe Hurd. I wonder which will be first, Hurd or Neo900.
GNOME/KDE/... now have systemd as a dependency so it has to be installed -> okay, I can see this, but on the other hand, why not? Who on earth manually installs these behemoth desktop environments? And -> they all also heavily depend on Linux