> I doubt there would even be an idea of good without humans or other sentient beings.

That's just as absurd as saying that numbers wouldn't exist if there weren't people to add them. That we perceive such things is immaterial; they are, independent of us. Just because the natural law is written on the hearts of man does not mean we are the source of said law.

The number of people holding a given view says nothing of whether that view is true or not. Truth is independent of human opinion. Just because someone chooses to view that the sum of two plus two equals five does not make it any less false.

And just because the absolute truth is unknowable in its totality by the human brain does not make it any less real.

There are objective and subjective components to beauty, but things are beautiful only in as much they represent the form of beauty. Anything that is at all truly beautiful is beautiful in the objective sense. Some people perceive beauty where there is none, and fail to perceive it where there is much. This is due to improper formation, human imperfection, and the lack of the ability of the intellect to grasp the form of beauty.

I agree with your assertion that the national endowment of the arts and other such bodies in modern times are terrible, and produce worse results than the market would in our current age. But we are also in an age and place that has little in distinct culture, and little in terms of objective values. I have a problem with the US government paying random kiss-ass artists to wipe their asses in a paint bucket, but I have much less of a problem with King Ferdinand IV of Naples commissioning Joseph Haydn to compose a series of concertos for his wife.

There is little representation of the form of either beauty or truth in modern-day Iran or Soviet Russia, but one could make an argument from pre-revolution Russia. As flawed as many the Czars were, the art, choral tradition, architecture, literature, etc. that was produced in that period is certainly unmatched in the modern or postmodern ages.

Not all people believe that art is 100% subjective. There is a subjective component, as a matter of personal taste. But some believe in objective beauty, and things are beautiful only in that they resemble an image of the form of beauty.