Basically someone jacks off onto some canvas and calls it art. And maybe this was interesting when it first happened, and sold for millions of dollars, but to me the rest that followed was all in the same vein of P.T. Barnum's "there's a sucker born every minute" and the Emperor's New Clothes.
The "artist" has taken nothing, ascribed meaning to it, and then sold it for money.
If you like to do something like this, and you feel it expresses how you feel, more power to you. Just don't tell me it was difficult to do or required any kind of skill. Sure, you may have spent hours at it, thinking about it, rationalising it's meaning to someone else, and to you it might be worth a million dollars, but it's not a pure communication, as art should be.
A newspaper comic strip has more validity in this realm than modern art, often because it takes well known cultural perceptions and looks at them in a different way. "Modern art" is completely dependent on the artist to explain their work (or not explain in a sense of irony, I guess).
If aliens landed and were peaceful, and really wanted to get to know our culture, and how we felt about it, would they look at a pile of bricks and know it was supposed to represent the labor of (hu)man?
Or would they get more out of Dilbert?