Some tastes change but not _all_ tastes change. This is a common misconception in conversations about taste: “some of it is subjective therefore it must all be 100% subjective and meaningless”. Yet when this comes round to something you’re good at (music, painting, literature, cooking, sport, …) you immediately recognize that there are in fact timeless elements. Universal truths, which are characterized as subjective only by those who cannot see it.
Elements of taste are subjective. Not all of it. You recognize this yourself in your own area of skill. Everyone has one area where suddenly they agree not every opinion has equal merit, and can articulate why.
But move out of that subject and into one of their blind spots, and we’re right back to “that’s just taste, taste is subjective, taste changes over time.”
Subjectivity is the refuge of the tasteless, who can afford to let others do our thinking for us. GP was right on point in that regard.