I've used systemd on Arch Linux for about a year now. It wasn't the end of the world, I can deal with it, but it's not fun.
I'm bothered by seemingly built-in units that have no corresponding unit files, which all default to enabled, including units for bootsplash stuff ("plymouth") that isn't used on arch linux. I'm very annoyed by mounts and such that don't even have units, files or otherwise, such as the "pstore" filesystem or autofs4. I'm super annoyed that since an upgrade half a year ago, the configuration option to disable use of some cgroup controllers was removed, and now any cgroup controllers supported by the kernel are used unconditionally.
I have good reasons for not using some of these things, but even more than that, one of the main reasons I like to use Arch Linux is that I like to add what I need, rather than try to make sense of and clean up the clutter of a typical operating system later. The lack of control and default-everything-on of systemd is really very annoying, and I'm bothered by the strategies mentioned in this article by which systemd makes itself the one and only practical modern init system for linux.
I'd like to see Runit [1] and S6 [2] get more attention.
Docs and easy-to-apply tutorials would be a godsend in this area. I too really want to replace systemd on Arch. Currently, this is an uphill battle due to so many packages having systemd service files, and the fact that I've never replaced an init system before makes things that much more daunting.
If only there were more information out there, or more ready-made solutions [3], I'm sure there are plenty who would be ready and willing to give this a shot.
The only Plymouth-specific code I see in systemd is related to asking the user questions at boot-up time, like their mount password, and it works by sending a socket message to a socket plymouth opens, and successfully falls back if it doesn't exist.
On my system, those units do have unit files, and they're provided by the Plymouth package. I couldn't find any reference to "plymouth-quit-wait" in the systemd source code, so those strings have to be coming from somewhere. Are you sure you don't have a unit file at /usr/lib/systemd/systemd/plymouth-quit-wait.service ?
I'm bothered by seemingly built-in units that have no corresponding unit files, which all default to enabled, including units for bootsplash stuff ("plymouth") that isn't used on arch linux. I'm very annoyed by mounts and such that don't even have units, files or otherwise, such as the "pstore" filesystem or autofs4. I'm super annoyed that since an upgrade half a year ago, the configuration option to disable use of some cgroup controllers was removed, and now any cgroup controllers supported by the kernel are used unconditionally.
I have good reasons for not using some of these things, but even more than that, one of the main reasons I like to use Arch Linux is that I like to add what I need, rather than try to make sense of and clean up the clutter of a typical operating system later. The lack of control and default-everything-on of systemd is really very annoying, and I'm bothered by the strategies mentioned in this article by which systemd makes itself the one and only practical modern init system for linux.