... because all this fragmentation makes it so much harder to play dependency games, doesn't it?
Here's how it works:
1) take a turd-of-the-week (dbus, etc.)
2) make systemd depend on it
3) push patches adding dependencies on said turd to as many packages as you can, solidifying the damn thing to the point where it would be very hard to avoid even on the systems that are not systemd-infested.
4) pick the next turd, repeat the whole thing.
With systemd on every box the whole thing would become so much easier - just cut (3) out, avoiding the need to convince a lot of developers and (oh, horror) to deal with their objections.