Moreover, the example of "In tests, cyclists cannot tell the difference between frame materials when the frame is covered." - who cares?

I probably wouldn't notice the difference between some quality swimming gear vs elite (gold medal quality?) swimming gear either. Running shoes, etc.

Since when does a humans ability to determine minute differences in materials actually matter? Why would we care would opinion the biker has of the material? If it's objectively better, and better is defined by measurable, quantifiable metrics - then what do we care? We're not talking about a wine-snob scenario. Where it's purely subjective opinion based. We're talking about performance characteristics that, when used in competitive scenarios, actually matter.

Now does it objectively matter to some "bike snob" just riding to work? Eh, maybe not. Sure he may make it to work 1m faster due to an objectively better frame, but who cares. Yet, the fact that the bikers use case is subjective does not invalidate more objective use cases for better frames/etc.