Horrid Marketing
I have only walked out on three movies in my entire life and I am closing in on 40. Had I not been at the movies with my mom to watch this movie, I would have walked out.
I am not surprised it is rated so low, but I think it's biggest problem was it was marketed as a different movie. Whenever a studio does this, it is because they know their story is not solid enough to sell itself. So they created a set of commercials that built the girl in the story up to seem confident and somewhat powerful. The whole "after you" comment before jumping was displayed on the commercial as a strong statement of will, when in the movie it was a nervous and scared child who has no idea what to do.
I can deal with a bad movie. I can't deal with a studio lying to me as to what the movie is in order for me to go see it.