Perhaps it ought be discussed whether all Art is good Art.
Art is a method. It has two aims:
(a) Show, not tell, how things are;
(b) Make it fun to investigate moral reality.
It's easier for us to understand a situation when we see it from the perspective of fellow human rodents, not dry philosophical texts. And we're more likely to read a story or hear a song than read something philosophical. Art is the wonderfully irrational, the emotional and aesthetic, and that's its enduring power: we get a gestalt
of many linear thoughts at once, and can learn greatly from it.
Is all art good? No, art is a method. I can make art encouraging stupid, destructive things (like Ayn Rand, Toni Morrison, Chuck Palahuniak, Phillip Roth, Robert Heinlein, Jodi Piccoult, Stephanie Meyer, the list is endless) or I can make art encouraging us to rise above ourselves, seize life by the balls, and create a morality of more, better, faster, more complex, rising health -- like William Faulkner, Ernest Hemingway, William Blake, Michel Houellebecq, Louis Celine, and others.