If you are referring to the lack tight coupling being the ability to remove journald, time sync, etc, then you are correct. I should have been more clear I was talking about systemd as a whole, and not just those other subsystems, but I'll assume you meant the latter, in which case, yeah, it's possible to stop using lots of the systemd subsystems without too much pain (which I have done quite frequently, and found great stability improvements.) To be frank, I just really don't like the handwaiving away of valid criticisms people have (on any topic), with such dismissive language as "People keep saying ... but never supply any proof for that." This to me reeks of intellectual dishonesty, but again, that was my response because I probably misunderstood you to say that about systemd as a whole instead of how you meant it which was focused on gp's comment about subsystems.

One note: many people pretend sysv init has been dead and left behind, but I've seen production systems in major places still using it (not just embedded either). It's not nearly as dead as people might like to think.