> In other words, one could create new infrastructure to support those features and rewrite every single init script to use it. Administrtors would have to learn a lot again about what new magical commands one would have to use to start a daemon.
Yes, but that can be done as a limited incremental change in the init scripts. Users would still know where to look and what to expect. In case of systemd, the approach is to wipe out everything and replace it with something completely different.
> But why not use this chance to go a little further and make another leap in usability and features?
Very simply, to allow people to use their existing knowledge and preserve backwards compatibility.
Too big a leap and you get your customers against you. Remember GNOME 3, Windows 8, etc.
> I still remember the WTF look on my dad's face, when I showed him how to fix the ordering of the init scripts
That's not a big problem. A big problem is when I get WTF face from my sysadmins. :)