Isn't that just a lot of words to say "my taste is objective / rooted in reason, other people's tastes are a crapshoot"?

Can you prescribe some specific test to tell objective design aesthetics from the "groupthink" ones? If not, then what are you saying, other than "I know when I see it, but not everyone does"?

Sure, there are things we do in a particular way because of manufacturability or utility considerations, and that stays pretty stable in the long haul. We put windows in homes in specific places and make them rectangular. But that's not taste, that's practicality. Everything else changes dramatically from one decade to another.

The short answer to your question is "no". The long answer is "read Zen And The Art Of Motorcycle Maintenance".

When you spend a lifetime learning design you learn the difference between taste and fashion. Taste is the ability to make solid choices coherently within a system being it fashionable or not.

Fashion is just the latest system that is popular.

Tasteful people can design good things regardless of the fashionable era. Great ones can create new fashionable eras.