To be fair there's real issues with this approach, too. For example, shell scripts aren't actually very portable. GNU awk vs nawk vs... multiply that by all your tools, and yeah those scripts don't run deterministically (they rely too much on the environment). This alone was a big reason why systemd exists today.

But there's a middle ground here too. To me there's a HUGE gap between Kubernetes distributed systems and shell script free for all.