I'm not so sure this is entirely true, especially with pid namespaces becoming a real thing. The true pid1 could be greatly simplified for the sake of system stability while providing sub-pid1s that handle actual service, device, and application management.
I mean if you protecting yourself from panic by moving stuff from real PID 1 into pidns root, you're doing it wrong.
pidns root will segfault and kernel will SIGKILL everything inside which is equivalent to good old panic.
