Those are all not million lines of code applications, but that only speaks in favor of a more traditional Unix userspace design. With modularity on the process level you don't need a million lines of code to herd services. Why an init system should a million lines of code is a mystery to me.
Isn't that basically what SysVinit and a good-sized chunk of the management tooling in Linux is?
To their credit, Bash is a _weird_ language, but it's not going to corrupt memory when it crashes, and its failure modes are pretty well understood by the distro maintainers writing those scripts.