You are correct in your views on visual art, which by definition is images filtered and sifted through a human mind to make a specific point to the viewer that the artist is trying to project*. Art is not a way to get a good description of reality.

Still, one can tell a lot about reality, specifically about people and their attitudes and philosophies, both by the kind of art that is produced by people, and especially by how people respond to art.

If you know what kind of movies a person likes, what paintings he likes to look at, what sculptors he loves, what books he reads, you have a pretty good shot at knowing a great deal about his other opinions in life.

Ayn Rand's "The Romantic Manifesto" not only made this point about art, but showed the kind of art Rand felt was the best kind, and should be liked by people who had the right attitudes about life. Most of her points I agreed with, but found one or two others a bit weaker. For example, Rand portrayed herself as a fully-integrated personality, which had no room for the kind of dumb little enjoyments others might simply call "guilty pleasures" and be done with it. Her attempts to justify her less-lofty tastes by philosophical analysis were kind of humorous, leading to the artistic ennoblement in her writings of such authors as Mickey Spillane Now, although Rand made some excellent and consistent points on why she liked Spillane, and although Spillane is certainly no hack, I still suspect he probably didn't deserve half the credit Rand gave him.

*Those who slap something together, and then when asked its meaning, say "it means whatever you want it to mean," or "it depends on who's looking at it" are not artists. They are barely fakes. A real artist will always be able to tell you exactly what his work is supposed to do to your head, and in words real people can understand.