They're talking about musical performances here, but I think it applies very well to Internet book review sites as well (especially Goodreads).
Dear Miss Manners: As I have a long career as a musician and music scholar, I may be asked my opinion of a performance. I reply with a measured response, a statement of approval or a sharp criticism.
However, as an audience member there are occasions when I feel obliged to express criticism of the performance, or of excessive approval exhibited by the audience when I believe their unison response lacks understanding.
Why should it be acceptable to give standing ovations, etc., at the close of passable performances, but not shouts of critique? I refer only to professional concerts and not school or amateur performers. My wife says I am rude and feels humiliated upon these circumstances. My therapist comments: “Do no harm.”
Online commerce has conditioned us to the unavoidable running commentary from “unsatisfiedcustomer447” on how the toaster did not work as advertised, but not every interaction with our fellow man is subject to review.
Nevertheless, curtain calls certainly are, and Miss Manners will defend your right to boo as well as to cheer.
But it is not a debate. The person sitting next to you has as much right to express his opinion as you, no matter how ill-informed it may be. Booing your fellow audience members would be impolite, and will, in any case, not be heard over all the “bravos.”