Writing init scripts for various init system is a lot of work. You are free
to do it. GNU, and not particularly Linux, is about freedom, not choice.
And the way a system starts with systemd is far more understandable than the
way it does that with the old System V init. It is a declarative syntax to
specify a nice dependency tree vs. a bunch of Shell scripts with spaghetti
communications between them.
You can find many recent talks of Lennart Poettering on the Web to learn more
about systemd. For instance: https://access.redhat.com/site/videos/403833 and
three videos in
http://meetings-archive.debian.net/pub/debian-meetings/2013/debconf13/webm-high/
