And it's also a lot considering that most (?) of those lines of source are compiled into a single inscrutable binary. One of the great boons of init.d shell scripts is that you can just look at them when something is going wrong, and quickly realize that they have a bug.
If something's wrong with a unit file (and/or systemd itself) it can be extremely difficult to debug. The unit file for a reasonably common piece of software (ganglia) is broken, and apparently still is after years. I've no real idea of how to debug this, and certainly don't have time to fuck with it. At least in this regard, systemd sucks.
The init binary of systemd itself is ~70k if my math is correct & still has a much richer feature set.
I don't know what init.d shell scripts you've been looking at but my experience has not been as pleasant. Also, if you as an end user are looking at init scripts there's something massively wrong with the init system. Never heard of Ganglia but they seem to be on github. Have you filed a ticket with them? Have you messaged them on whatever forum/IRC the devs hang out on with your issue?
Yeah, I'm not crazy about the various init scripts that have been produced over the years. But at least when they're broken, I can usually just glance at them and see that. With systemd, mostly one just gives up.