The purpose of criticism is not to tell you whether you will like something or not. It may touch on this, but that is a side affect, not the main purpose. For a variety of reasons, movie reviews sometimes are about whether you will like the movie or not, and offer nothing in the way of criticism (in the traditional academic sense). Sometimes reviewers who combine both, sometimes in the same review. I can see how this can create confusion for the casual review reader, as you have to try to figure out when a review is offering criticism and when it is just a review.
Movies made purely for entertainment often don't have anything worth critical appraisal, other than technical execution, which is why those sorts of movies often have poorer receptions from the critics than from the public. (Personally, I prefer a movie that has a bit more meat on the bone, and offers something to think about critically. I recall enjoying the first Avengers movie, but I can't recall a single thing that happened in it.)