The Modern, a couple of years ago, had an entire "installation" of a huge pile of garbage bags. Okay I guess this was representing some non-representational thing. Overnight, this was lost on the custodial staff who proceeded to throw them all out thinking they were garbage, left from some construction. Hysterical.
In the course I took in modern, installation art-which, I will add was quite fun doing all sorts of useless things and calling it "art"-I asked the teacher why was realism so frowned on and instead, these "statements" being made. His response? "Years ago, artists moved paint to make a statement...we've done that...we now take that a step further and we move electrons".