Clotilde Dusoulier recently posted a wonderful article on how to taste chocolate, which emphasized the impressive skill of professional chocolate-tasters:
[T]he sample beans go through a mini production line, and emerges as chocolate the tasters will grade along thirty different descriptors. A tough job, I'm sure -- and I'm not being ironic.
Thirty! Chocolate tasting involves thirty different descriptors, but if you asked this panel of critics, their job would depend on being able to come up with nearly the same answer. You would be hard-pressed to find the same consistency among most literary criticism, with possible exceptions of a few canonical works.
Music has a canon, yet Western music has rubrics by which new works are compared. The rise to a major fifth here is pleasing; the dissonance of the tonic note and its fourth is resolved to create euphonic melody. Or something is dissonant or different, but still moving, so people ask why and change the rubrics (cf. Stravinsky and Cage). Films—though to a lesser extent than music—are similarly critiqued by familiar breakdowns: acting, direction, production value, depth/believability of narrative, soundtrack, etc.
We do not possess, or aspire to, similar consistency in literary criticism.