Janet's Reading #2, Clark on "Clement Greenberg's Theory of Art"

So I have read it twice. I had hoped that reading it the second time, it would be much clearer. Even after I purchased McGuire’s class book, “Why is that Art?”, and read parts of it for an overview of the Contemporary Art and criticism. I am really frustrated!! I understand Terry Barnett’s book about contemporary art, and it has been very helpful. All the various philosophical approaches to art and how they relate to contemporary art are very clear, not like the reading, “Postmodern Perspectives”. I know that we do not create in a bubble, but if I wanted to write about life and such; I would have become a writer! Why can’t art just be about art? Why does it have to be about class struggle? There will always be a struggle of the classes as long as society focuses on material possessions and their importance. Help! Any thoughts?