Precisely.
Some people just don't seem to understand the purpose of critics. Kermode doesn't just read out a list of films and tell you whether or not you should like them, he critiques them. He explains why (he thinks) they're good or bad, what he perceives the problems with the film are, what he feels are the film's strong points etc.
And like you say, his taste is refined in the same way that a food critic's tastes are refined. You just have to understand that - just as you might happily drink a bottle of wine a professional critic would hate - you might enjoy a film that all the critics hate.
You just have to know who the critic is and how his or her tastes match with yours. If Kermode rants about a big dumb action film, there's a good chance I'll feel the same way about it. If he dislikes a comedy, however, I'll take his review with a pinch of salt.