Systemd is great if your use case is Linux on a modern Desktop or Server, or something which resembles that. If you want to do anything else that doesn't fit into the project view of what you should be doing, you will be met with scorn and resistance (ask the musl team...).
What isn't great, and where the hate comes from, is that it makes the life of a distribution or upstream super easy, at the expense of adding a (slowly growing) complexity at the lowest levels of your system that--depending your perspective--does not follow the "unix way": journalctl, timedatectl, dependencies on/replacing dbus, etc. etc. It's also somehow been conflated with Poettering (he can be grating in his correctness), as well as the other projects Poettering works on (Avahi, Pulse Audio).
If all you want to do is coordinate some processes and ensure they run in the right order with automatic activation, etc. it's certainly capable and, I'd argue, the right level of tool as compared to something like k8s or docker.
What isn't great, and where the hate comes from, is that it makes the life of a distribution or upstream super easy, at the expense of adding a (slowly growing) complexity at the lowest levels of your system that--depending your perspective--does not follow the "unix way": journalctl, timedatectl, dependencies on/replacing dbus, etc. etc. It's also somehow been conflated with Poettering (he can be grating in his correctness), as well as the other projects Poettering works on (Avahi, Pulse Audio).
If all you want to do is coordinate some processes and ensure they run in the right order with automatic activation, etc. it's certainly capable and, I'd argue, the right level of tool as compared to something like k8s or docker.