It was highly contentious for a number of years - largely because it had a lot more functionality and touched more parts of the OS than the init systems it was designed to replace. It was seen as overzealous by the naysayers.
I was in the never system-d camp for a long time because I felt like my ability to choose was being removed. Even some distros that provided alternate init systems eventually went systemd-only.
But I’ve come around - it’s fine, good even - though ultimately I had no choice or say in it.
It’s very straightforward and easy to write one’s own units. It’s reasonably easy to debug and often helpful when something isn’t working as expected.
Like all things in the world of software, many folks are going to try (and eventually succeed) to make a better mousetrap.
This particular init system’s design goals seem (at least to me) to indicate a focus on small, embedded and/or more secure systems where the breadth of tools like systemd are a hindrance.
Totally fair and exactly part of my original disdain. I was happy with SysV and Upstart. But here we are and I’ve got things to do. ;)
I hated repackaging all my software for systemd. lol. We waited as long as we could before eating that pie.