Some art being "crappy" is what makes it art. For example, the postmodern movement of the 70's saw things like punk rock music, where the average person would look at the Ramones or others and say, wtf...he's not even singing in tune and the guitar player can barely play 3 chords and doesn't even play them right. Some art is about smashing traditional aesthetic ideals. With formal training and "good" art comes a whole host of baggage, of conformity. For example surrealism was in many ways a reaction to the Renaissance perspective, idealism and "perfect" proportions.
But yes, some art does just suck. Alot depends on the intent of the artist.
