Recently we've gotten into discussions about artistic taste (see comments on AI Art Turing Test and From Bauhaus To Our House).

This is a bit mysterious. Many (most?) uneducated people like certain art which seems "obviously" pretty. But a small group of people who have studied the issue in depth say that in some deep sense, that art is actually bad ("kitsch"), and other art which normal people don't appreciate is better. They can usually point to criteria which the "sophisticated" art follows and the "kitsch" art doesn't, but to normal people these just seem like lists of pointless rules.

But most of the critics aren't Platonists - they don't believe that aesthetics are an objective good determined by God. So what does it mean to say that someone else is wrong?

Most of the comments discussion devolved into analogies - some friendly to the idea of "superior taste", others hostile. Here are some that I find especially helpful:

https://www.astralcodexten.com/p/friendly-and-hostile-analogies-for