Also if busybox is not enough, a minimal systemd system will still be leaner and faster than the equivalent sysV system.
http://events.linuxfoundation.org/sites/events/files/slides/...
IIRC it's also part of some soon to be shipping vehicle integrations, for in-car entertainment systems and mapping.
Also, it's inevitable that if systemd and software expecting to use it take over more and more aspects of userland and the kernel, vendors will be left with no choice but to use it as well. So "more vendors are switching to systemd" is not a convincing argument either. I like to make my own decisions on the basis of modularity and replaceability (vendor lockin has been a huge burden in other major projects not mentioned in my online persona), not popularity.
But lets say you are building a highly specialized application. You are going to be making quite a few customizations which are far more manageable through a shell scripting environment than by customizing a bunch of binaries.
I assume that Redhat is going to cover a lot of the bases for most users out there. But for those of us in highly customized environments it's going to suck.