This is, perhaps, one of the best metaphors I've read for explaining this concept.
As someone who does one of the "lower" jobs, I rankled at his "hierarchy" of roles notion. Never mind that I probably could write application code if so inclined (and do routinely write "infrastructure" code and sometimes have had to fix those developers' code in production).
I occasionally like to point out to "engineering" or "technology" [1] managers that not all problems can be (or are best) solved with software/code. Some of use, when we digest a problem, can poop out zero or even negative code.
[1] In quotes because they're nearly always actually only software engineering or technology managers.
My previous favorite: Linux is free as in free mattress.