Reproducible vs. Unique

There is a debate about modernist and post-modernist art; that because the art may be physically reproducible, then why is it so valuable? The answer is, that the art is not reproducible, and for several reasons. Most of what drive the art is the ideas behind it and the process in which the artist goes through to create it. For example, Jackson Pollock’s abstract works. They are about the paint itself, and how he created this pattern that seems random to the untrained eye. He created these paintings a certain way, almost dancing around the canvas, to make the pattern that some viewers see as chaos.
There is a similar story for post-Modernist and founder of Dadaism, Marcel Duchamp. He reason that his “Golden Fountain” (1917, a bronze-covered urinal) is art is “because I chose it”. This implies that anything can be art, from the epitome of reproducible, a mass-produced object like the “Bottle Rack”(1914). If there is reasoning behind how the artist chose it, or the process that they altered or created it, then it is art that cannot be reproduced. Because to make another identical “Bottle Rack” and call it art would make it a reproducible commodity to buy and sell to people in mass, which was what Duchamp was trying to escape when he created his works.