I’ve never heard of one either. While systemd is certainly more complex than old school init scripts, and arguably deviates quite a bit from the “Unix philosophy,” it seems some people just have an irrational hatred towards it. To the point of making up problems with it that I’ve never heard anyone actually having.
There are a few reasons why systemd left a bad taste in the mouths of many Linux enthusiasts:
Systemd replaces (or tries to replace) whole swaths of OS functionality all at once, instead of addressing each piece individually. As a result, all of the systemd pieces are tightly integrated and nigh-inseparable, and critics claim this was intentional so that distributions could not easily pick and choose the parts they wanted. My understanding is that this is better now. In my experience, some pieces are better than others. (Systemd-timesyncd is absolute rubbish compared to chrony, for example.)
Although the goal of writing a better init system is laudable, a lot of people who looked at it early on not impressed with the implementation (a lot of NIH wheel-reinventing) and mediocre code quality.
It was introduced into Fedora rather suddenly with seemingly little warning, community discussion, or press coverage. In the Linux world where big things change slowly if at all, other popular distributions seemed to adopt it fairly quickly, one after the other. This raised a lot of conspiracy-like speculation about how that could have possibly happened.
The developers are famously obstinate about their technical decisions and often argue in, close, or ignore bugs asking them to consider a different direction for specific low-level issues. There have been a few public disagreements over "correct behavior" when integrating with other projects (e.g. the Linux kernel).
Had a problem with systemd-resolved yet again the other day. Blatted resolv.conf and job done, but between systemd and related things (network manager etc) it just breaks the way things have worked for decades and gives many people no benefit.
This isn’t all systemd of course, it’s the distros that choose to use it.
Two systemd things that I disable straight away on every box: systemd-resolved, and systemd-timesyncd. The former tries to be "smart" and therefore tends to mess up DNS in very simple scenarios (such as a box in a datacenter with a static IP) and the latter is just plain rubbish compared to chrony.
It's been a blessing for me. It's so easy to see the process hierarchy, easy to create units and timers and dependencies, and with services being combined into cgroups the concept of a zombie process was basically eliminated.
I guess I get that init was simple, but it didn't care about the process lifecycle. You always needed to have an incredibly smart init script or watchdog service to manage that.
