I'm sorry, but are we still going on about this? I love a good debate as much as the next guy, but being able to just have one interface (systemd's) for all services and having a more-or-less consistent language really helps.
At this point, it's simply a bit too late. I'm sure in the early days it was still a choice, but when you want prepackaged things, you get systemd.
It's Linux bro, we absolutely need to have 500 different options for every single thing. Doesn't matter if every option sucks, diversity is above everything! /s
There are some truly special people among Linux users that think diversity in init systems/libc implementations/etc is a good thing for a general-purpose desktop. They don't understand that people just want stuff to work, and developers don't want to support more than 1 init system (or other trivial thing) for their package.
Success of Linux on the desktop is fundamentally incompatible with diversity, but unfortunately not everyone gets that.
You could also just use one system (Windows) for everything if you wanted. Some of us decided to use Linux because we want things to work how we want and not how some bigshot decides they should work.