It is not the film critic's job to in-touch with his or her readership. It is the film critic's job to provide a well-reasoned opinion and then to communicate that opinion clearly and concisely, such that there any person reading the review can come away understanding why the critic feels the way he or she does, with agreement entirely optional.
In the very best criticism, the person who has not seen the film will have points of interest (either in the film's favor or not) for which they can look, and the person who has seen the film comes away with something more to think about.
Indeed, the best match between critic and reader should be when the critic holds one opinion, the reader holds another, and the reader can still come away from the review feeling like they've taken part in a conversation or debate about the film, without anger or reproach.