So is UNIX design only great when it serves the message?
If you're going to argue that Linux implementing systemd is a good idea because it's following the trend in "proper" UNIX descendants, then the same argument can be made for it following the trend of BSD-style init systems. It ultimately boils down to which direction you think is better. I'm of the opinion that simple init systems, of which there are plenty to choose from, are a better fit for the Linux ecosystem than a suite of tightly coupled components that take over the entire system. If we disagree on that, then we'll never be on the same page.