We watched an Art21 movie on three artists.  Katarina Grosse makes gigantic sculptural paintings involving trees, dirt, and the space of the art gallery itself.  Joan Jonas makes performance drawings involving dancers, musicians, and herself in her installations. Omer Fast makes experimental/journalistic-like movies about Drone Pilots or Porn Actors. We agree that performance art is problematic. Becoming the body that is viewed as the art is a little bit problematic. Where is the line? How much of that happens out of peer pressure? My definition of art is pretty broad and I would not say performance is "not art" however, I would definitely say that I cannot engage in it the same way that I would with physical space. 

http://www.art21.org/artists/katharina-grosse