Ultimately all that matters is if one is entertained. If people went by critics, they'd never go see any movie out there. Yet, the majority of films made today that make the most money are usually hit hardest by critics.
I for one, prefer to be the critic for myself.
I agree, I alone decide whether or not I like a movie. And yet, a bad movie can be entertaining... but still be a bad movie. Critics don't slam movies because they make money, Titanic was applauded by critics and made tons of cash, but I still found it to be a drawn out, tiresome movie.
People give movies poor reviews because they're bad movies, not because they make money
Also, I give credence to Rotten Tomatoes over any other review site because they calculate their overall score based not only on the reviews of professional movie critics, but also the reviews of everyday people (which makes up the majority of the score). They have an extremely large number of people reviewing the films. Their scores are averaged based on 100's of reviews (both professionals and the public), instead of 4 or 5 like other sites.