In my opinion, as an init script replacement, systemD is almost a great thing. Including everything else is what makes it a terrible thing.

But...it doesn't include "everything else". My desktop doesn't use systemd-timesyncd, I'm not even sure systemd-nspawn is installed on my home server, that same server isn't using systemd-resolved. I haven't fiddled with journald anywhere 'cause I like it a lot more than rsyslogd, but you totally can forward journald stuff to rsyslogd if that's more your bag (and I think, though don't quote me on that, you can remove it entirely if you want).

Yes, there are additional, thoroughly optional, components to the systemd ecosystem that you can choose to opt into. And...so?

You can't replace journald. See the 10 times this has been referenced throughout the thread.

The thing I don't get is how bothered people are by it existence despite being able to just forward logs to syslog and then ignore it forever.

    [Journald]
    Storage=None
    ForwardToSyslog=True

And then it's like it was never there. But technically it's better than if it was never there because you can still capture service stdout/stderr and it will show up in the syslog where on an older system it would just be dropped.