I'm not an artist, why would I work out objectivity for art (Like this is what specialists in a field DO, they make up measurements that when used give people a good idea of qualities and let them compare them)? The golden rule is not a fallacy, it's just not an absolute causation, it dramatically increases the chances though that your "art" will be pleasing (Which infers there ARE objective principles in art that have large effects). The three act structure in a movie offers a start to make a decent film, too. This doesn't mean you can't make a film that disobeys it and is still good, nor does it mean your film will be good with it--but if you look, there is a significant correlation in good films and three act structures, and how it affects the audience. (If you put a drug on trial, and on one group the placebo does 0 and the other drug cures people 70% of the time, guess what? That means the drug doesn't always work, sometimes people still die. But it works at such a high rate, we can TELL a mechanism in the drug is working against the disease. Just because not ALL golden rule paintings are good, doesn't mean there isn't a standard there.)
Understand? But making up measurements, and structures? Already makes an objective quality to art. Meaning beauty isn't totally subjective. It obviously has rules. People who work IN art used to delve into those rules, classical artists actually began codifying them before post modernists shit on everything. Artists should once again start doing that, start really digging into what people enjoy, what speaks to the broadest group and begin isolating variables so they can develop measurements. This won't mean some niche won't have separate measurements, but it will mean artists might create something coherent that might be able to predict enjoyment within a ballpark (Still subject to subjectivity, but certainly a strong starting foundation, like our three act structure.)
Simply saying "there are no standards, anything can be art as long as I know the guy?" is laughable dog shit. That's the idiotic shit people like Tanoomba believe because they truly believe the world should be a social club, and deciphering an actual measurement or way to PREDICT enjoyment? Is bad. And that's what it why people treat are like a profession end up making consistent money, and people who treat art like 'an expression of their soul' usually end up poor. One is concerned about finding of why people enjoy something, the other is concerned about impressing their friends "in the scene".