Another issue is that a critic who sits down to review something is very much like a student who has been assigned a book for the purpose of writing a paper. I'm not saying you can't enjoy an assigned book, but you do read it differently than someone who is reading for pleasure. If a critic has time to read for pleasure first and then read again as a critic, they can reduce the problem, but this is rare, I suspect. And anyway, they still know they are reading for the purpose of reviewing when they are reading for pleasure.
Finally, critics not only have to judge a work, they have to write about that judgment. This brings a level of artificiality because the critic has to create a narrative that will interest the reader. Maintaining the narrative can become more important than giving a true sense of the quality of a book or record. In other words, good writing sometimes beats out good criticism.
But there are critics who love what they do, have the time to do it, write well, and know what they are talking about. What is their role? Off the top of my head, I can think of three legitimate ways critics are valuable and conveniently they all start with "e":
- Entertainment. It's enjoyable to read good writing about art by someone who is informed.
- Education. The best critics are able to see things in art that many of us would otherwise miss. Reading them deepens are appreciation for art because they teach us new ways to think. We don't have to agree with them, we just have to be stimulated.
- Empowerment. When a critic agrees with you, it makes you feel confident in your own ability to process art. If you are more confident in yourself, you enjoy things more.