To make it clear, I never said that systemd doesn't bring improvements. systemd does offer numerous quite-nice-features.
However, in my opinion it was completely unnecessary to wipe out existing SysV principles in order to implement those quite-nice-features.
Actually it seems to me that the main reasons to throw SysV concepts out were to implement features which many users don't really care for, like use of targets instead of runlevels.
You can implement a daemon which would launch scripts from /etc/init.d/rcS.N and use /etc/inittab, you can introduce special functions in the scripts to support reliable service launch and PID capture, you can still have this daemon to listen for callbacks from the services to indicate succesful startup, catch service startup output in a structured log, etc. You can even provide OPTIONAL ability for parallel startup for those who want it, while keeping the traditional startup sequence by default.