I would love for such a thing (and have thought about doing it myself). But as systemd's capabilities grow more and more expansive, and with its lack of modularity, it becomes harder and harder to write a replacement for it. Of course, even replacing only a piece of systemd's functionality (for example its process manager) would still be beneficial, but systemd would continue to be the only real choice for many.
The way you overthrow an overlord you no longer like is by knuckling down, working hard, kicking out a replacement. This is how LibreSSL came around (http://libressl.org).
There's nothing especially wrong with the idea of systemd or the way it's been deployed, but if the code-base is suffering from neglect one way to fix that is to either support the core team, or barring that due to hostility, fork and/or make a work-alike.
I would suggest that simple common sense might prevent such a thing. It's not without reason that the older, wider heads always kept initd simple, in part to prevent it becoming an unnavigable monstrosity. The very idea of the "legacy" init implementations creating files, let alone suid root files, is laughable.