I think one thing that gave systemd adoption a big boost was a declaration from the maintainer of the cgroups sub-system of Linux.
At present multiple processes can set up and manage cgroups, but the maintainer wants to change to there being a single user space manager.
Thus systemd was pushed as "the" cgroups user space process.
You can already seeing the systemd devs behaving as if this was a done deal.
Ran into a email a while back about systemd clobbering a libvirt managed cgroup. And in it Poettering "suggested" that libvirt should hand control over to systemd as it would be THE cgroups manager going forward.
You can probably find similar encounters between, say, Docker and systemd.
At present multiple processes can set up and manage cgroups, but the maintainer wants to change to there being a single user space manager.
Thus systemd was pushed as "the" cgroups user space process.
You can already seeing the systemd devs behaving as if this was a done deal.
Ran into a email a while back about systemd clobbering a libvirt managed cgroup. And in it Poettering "suggested" that libvirt should hand control over to systemd as it would be THE cgroups manager going forward.
You can probably find similar encounters between, say, Docker and systemd.