I notice that no-one has picked up on an assumption at the start of this thread:

"do we need anyone to tell us what we should like or not like [?]."

The assumption here seems to be that the function of a critic is to issue instructions and to dictate preferences. That's certainly not how I see the critic's role!

This idea that criticism, or even disagreement, is always hostile, punitive in intent, and dictatorial is very tiresome and more than a little immature. It's the sort of response that I would expect to come from an insecure, adolescent fashion-victim.

Surely, the role of a critic is to provide as objective an assessment of an artist's work as possible. A good critic should be able to convey to a potential audience a feeling for the quality of a piece of work and an assessment of how well, or badly, that artist has suceeded in meeting his or her objectives. A desirable secondary outcome of an effective piece of criticism may also be to provide useful feedback to the artist.