My half tongue-in-cheek comment was implying things like "you can't boot a linux/bsd box without shell scripts" which would make the whole "serving a website" bit hard.

I realize that there exists OS's that are an exception to this rule. I didn't understand the comment about scripts scaling. It's a script, it can do whatever you want.

Shell scripts don't scale up to implementing complex things, IME. If I needed to do something complex that had to be a shell script for some reason, I'd probably write a program to generate that shell script rather than writing it by hand, and I think many of those system boot scripts etc. are generated rather than written directly.