^^^ As a mainframe systems guy, I used (and mastered) more Op. systems than I could ever recall over my IT career. Mainframes, high end servers etc.... many offloaded/ported to Unix based stuff running in a seperate "partition" decades ago. Unix was too "simple" ... so I never became a Unix guru...
I was a communications systems programmer ... as the communications protocols, hardware, and speeds evolved.... Unix thrived behind the scenes under other extremely sophisticated Op systems.
KISS ... that's Unix for ya
All of the Internet related stuff (Web servers, TCP stacks, etc.), run on some flavor of Unix ... even on big blue.
But it ain't KISS
