The impasse was broken by, amongst others, a young art historian called Ernest Gombrich who put forward the view that works of art (photographs included) should be assessed, judged, valued (whatever) by their function. Gombrich ask the question, "What is this work of art for?, What purpose does it serve? Why has the artist made this?" He wrote a book called "The Story of Art", first published in 1950 and still available today in goodness know what edition. (Google on Amazon and you'll find it.) Even today, a decade after Gombrich's death, this is considered a seminal book for people wishing to understand art. You should get a copy and read it from the point of view of a photographer - it will change your way of thinking.