init.d was familiar to graybeards (like myself), but I'm loathe to consider them a superior solution.
I've been looking for these for years: the reasons that might justify the removal of basic functionality and interoperability with other tools. Got any sources?
From what I can see, the dislike exists for far more practical reasons.
In my experience, it has a tendency to break in ways that the numerous other init systems I've used over the decades never did.
When it does break, it can easily prevent a computer from booting, which makes that computer pretty much useless until the problem is fixed.
I've found that it has often been far more difficult, and takes far more effort, to debug and fix problems with it than with other init systems.
Its tendency to become more invasive over time has also opened the door for even more problems involving it, well beyond its role as an init system.
Given the large number of bug reports, questions, complaints, and so on about it that I've seen over the years, people don't dislike it just to be "fashionable". They dislike it because it's making their lives unnecessarily painful.
https://systemd.io/CONTAINER_INTERFACE/
You can argue that a process manager for an unprivileged container should be more like supervisor or systemd user services. However, it would be really convenient to be able to globally install unit files (say, using a deb package), and have them work whether it's bare metal, a VM, or a container.
It forces you to think of stability instead of creativity, and that might be great for people who value predictable things in their lives, but it stands rigidly in the way of fun.
Technically, I guess it’s interesting to design if you are an expert but as a user, having to use creativity is the last thing I want from low level pieces of my OS. If you want to tinker with OS design, you can always install Minix in a VM.
I don't know about fun, but different people find different things fun.
I find systemd to be often irritating, and sometimes infuriating. It has not made my life easier at all. Just the opposite. So, in that sense anyway, I'd say systemd is much less fun.
Every distro did init scripts in different, exciting ways, so I had to start over from reading the not-inconsequential docs for each one. The init systems come with some high-level helpers, but only if you want to use the shell, which is very unfun in its own right.