I believe quality control is a customer-facing concept and customers aren't who employers optimize for.

This is what the original article and most comments are missing here in my opinion. Theories of value matter: https://en.wikipedia.org/wiki/Value_(economics)#Theories . To some degree I might agree with subjective value theory, so in essence everyone values things differently.

However as a framework it describes outcomes without being able to critique them, so whatever happens in a market gets called efficient by definition, including monopoly rents, regulatory capture and the steady drift of returns from labor to capital.

In my opinion labor theory of value describes the underlying relation correctly. The fundamental relation is between employer and employee and the structural goal of that relation becomes extraction of surplus. Customers and product quality enter only as the means through which surplus gets realized.

Once you see it this way, the just-say-no engineer situation makes sense without bringing ZIRP into it. They were doing customer-facing work, defending product quality, inside a structure that doesn't actually want it. They were tolerated, not central. When tolerance shrank, so did they. Good products are incidental to extraction, sometimes useful for it, sometimes in the way.