.I worked with Linux-HA before systemd, and I of all the problems, I don't recall init scripts being one of them.
The problem isn't init scripts it is what to do with chains of dependencies on high availability. If you worked in Linux-HA think about the application specific restart code that each application had to do and how fragile it all was.
That's an interesting thought.......have you ever supported Oracle Financials or similar? Do you have experiences you can share?
I help people migrate to cloud. IaaS/PaaS is a godsend in getting complex application stacks working. I can offer experience there that what I'm finding is not that people want a lighter thinner init-system but they want an process manager which is capable of intelligently handling
resource orchestration, resource monitoring, resource provision and resource balancing
virtual machines: backup, restart, status...
storage virtualization: especially backup
continuous delivery especially decommissioning a
database monitoring ....
They all want an much richer environment of management tools. In real life I've never met anyone who thinks systemd is too thick, they all argue it is too thin. The amount of time IT people spend worrying about basic things like messaging across security zones is infuriating to management. Mostly now that Linux is taking on the workloads of mainframes I'm finding most companies want Linux to offer the kinds of services you would find on mainframes (but more modern).