I'm gonna stick up for Modern Art here a little.
1) Duchamp and his ilk what most people consider "bullshit" art. IE Hanging toilets, and blank canvases, and even indicating empty space as art.
Yes on some level it is complete bullshit. I'm personally unmoved by this particular vein of art it and think it spawns a lot of lazy thinking. But I would defend to the death the idea it forwards. No one can say what is or isn't art. What has or hasn't got value. These guys are the punk rock of the art world. Maybe that's not right. They are the first industrial musicians of the art world. They are Throbbing Gristle. Without their expansion of the conception of art other artists wouldn't be freed to play around in ways you or I might consider more legitimate. Without their noise we wouldn't have Nine Inch Nails, Aphex Twin, or Massive Attack. If you'll go with that comparison. And even if you can't find the value in what they produced, they deserve your gratitude for expanding the vocabulary with which you express yourself.
Also, dismissing anything is bad for your brain. When you look at art that is by it's nature unintelligible you are forced to think in new ways. Opening yourself up to the possibility that the valueless has value keeps you from stagnating. If you as an artist want to be able to show the world a new idea. You have to be open to them first. If that means you look foolish or pretentious then so be it. Better to look foolish than to actually be a close minded idiot. If that means you start understanding something that used to disgust you and your peers. Good. Then you won't ever be afraid of looking.
2) Robert Motherwell, Mark Rothko, Fancis Bacon, Picasso, Louise Borgeous, etc. I love these guys. If you dismiss them as a group or as individuals you might miss out on something you really love. Something that excites you. All because you've closed your mind.
3) Non-representational art is fucking hard. If you don't think so give it a try. Try to find a new way to make an image that doesn't rely on your interpretation of something real or imagined. It's pure composition, and the shit's hard to do well. I personally suck at it.
Find a non-representational artist you enjoy. Or try your hand at finding a new way to make art in a non-representational way. You might get a new appreciation for it.
END RANT ... probably