Discussion about art is certainly not science. It doesn't have the safeguards science has against biased judgments. But that need not mean that art criticism is intrinsically subjective, and that anything goes. There are intelligent judgments and insights, and the opposite. A wonderful discussion of this is:
David Hume of the standard of taste
That bit by hume is nice, thanks.
By objective I mean can we make a neutral judgment and prove that one work of art is better than another? For example, we can prove that most people like one song more than another song, but does that mean that we can positively say that the more popular song is better than the less popular song, or only that more people think so?
Let's say we are told a joke, one that involves sherlock holmes and watson. If you know the characters you find it funny, or funnier than if you don't. Knowledge can aid in appreciation of the joke. I would say it's the same with art, when it involves more than pure sensation. But a piece of art that requires knowledge to appreciate is not better than one that doesn't (despite the common conception). So, experts can judge some
art better than most people because they at least "get" the work. They are still a prone to a huge amount of bias of course. And it's my impression at least that a certain type of person becomes a film critic for example, or the process of becoming one changes the person, it would explain why "transformers" makes millions but gets panned by the critics anyway
So it seems like we can't say that one song is intrinsically better than another, just that one is liked more by more people.
Well, that works for the "sensation" part of art at least. But artwork often has a message attached, and if that message can be objectively judged then so can the art. I think hume was saying something about this at the end of that piece. If a romance movie is saying something about human relationships that is false (shown false by psychology or neuroscience, say) then that would reflect poorly on the movie.