For me, it is pushing Linux in the opposite direction of the main reason why I like Linux.
I was attracted to Linux because unlike Windows or macOS, I actually have choice with Linux. I can choose my filesystem, my libc, my init system, my bootloader, my system encryption, my window manager, etc.
Sure, it's not perfect: many programs assume that you have glibc, or dbus, or X11, or wayland, etc. Actually many programs assume that you run Ubuntu. And it is frustrating when you would want to use a program and can't because of such an assumption. But again on Linux, there is (or used to be?) a big open source culture. This program is assuming glibc? I can patch it to work with musl. Etc.
Systemd, to me, sounds like it says: "why would I care about interoperability? I am the best, you should use me. And if you want something else, you should make that something else interoperable with me, because I make the rules". It's not like systemd is trying to standardise stuff to allow alternative components to exist, right? It doesn't actively try to prevent alternatives, but that's pretty much it.
And normally I wouldn't care (again, Linux is about freedom of choice for me). But systemd being as successful as it is dramatically reduces my freedom. And systemd it seemingly trying to take over more and more components. And the more adoption it gets, the more power it has. You didn't want systemd to replace that part of your system? Too bad, it will. What are you gonna do anyway, systemd is too big to care about you at this point.
A lot of people prefer to stick to the old sysV-like initscripts setup that most distros used before systemd (and is still an option on some, though with extra steps like adding orphan-sysvinit-scripts in Debian and manually removing the relevant systemd parts as IIRC there isn't a standard install-with-sysvinit option without installing a much older release and upgrading via a couple of dist-upgrade cycles (which keeps your old setup as much as is practical)). It works for them, has less bloat that they might not need, can be easier to debug, and they know it well, …, though isn't as well-supported any more with some packages that provide services just defining systemd jobs and you have to work out an alternative yourself. Debian even includes other init systems (like the one from Gentoo) - there is more than systemd out there if you want to try something different. Some people would still prefer upstart, which Ubuntu used for some time before moving to systemd.
I'd prefer to keep the older sysvinit init scripts, with all logs just going to text files rather than the systemd journal, but not so much that I make the effort to “fight” to keep things running that way on new installations. A lot of stuff still works the old way anyway (journal logs being mirrored to files in /var/log, init-like scripts in /etc/init.d calling systemd parts to mimic what the script on its own would have done previously so you can still `/etc/init.d/apache reload` or such).
Not OP, I run artix linux with runit. You can choose from 3 different alternatives in that distro, each one has its pros and cons (smaller size, easiness to setup and manage services, etc..)
The main idea behind inits other than systemd is that stuff in linux should aim to be small and modular and systemd is a giant that wants to do everything.
I was attracted to Linux because unlike Windows or macOS, I actually have choice with Linux. I can choose my filesystem, my libc, my init system, my bootloader, my system encryption, my window manager, etc.
Sure, it's not perfect: many programs assume that you have glibc, or dbus, or X11, or wayland, etc. Actually many programs assume that you run Ubuntu. And it is frustrating when you would want to use a program and can't because of such an assumption. But again on Linux, there is (or used to be?) a big open source culture. This program is assuming glibc? I can patch it to work with musl. Etc.
Systemd, to me, sounds like it says: "why would I care about interoperability? I am the best, you should use me. And if you want something else, you should make that something else interoperable with me, because I make the rules". It's not like systemd is trying to standardise stuff to allow alternative components to exist, right? It doesn't actively try to prevent alternatives, but that's pretty much it.
And normally I wouldn't care (again, Linux is about freedom of choice for me). But systemd being as successful as it is dramatically reduces my freedom. And systemd it seemingly trying to take over more and more components. And the more adoption it gets, the more power it has. You didn't want systemd to replace that part of your system? Too bad, it will. What are you gonna do anyway, systemd is too big to care about you at this point.