I find critiques informative and very helpful when it comes to analyzing artwork and improving your own artwork.
Visual literacy adds depth to the art curriculum. Critiques provide real classroom perspective on dealing with meaning, gender issues, influences, and more. This discovery-oriented approach gets students talking, thinking, and writing about many genres of art, and hooks even reluctant students. I have seen this first hand in my field work placement. It is incredible how engaged students can become in a lesson once you ask them the right questions.