This movie seems to depend on blood, guts and gore. After the initial scene in which so much of the woman is seen without clothes, there is very little nudity and plenty of blood, guts and gore. The story seems to have written to support showing it.
One thing that everyone seems to be missing is that so many people are killed. We are supposed to feel for some and not care about others. However that is one of many things that make it difficult for me to enjoy them.
There are a few times in this movie when the police could have been and should have been called yet they were not. This was probably also done by the writer because it was an easy way to maintain the drama. Producers will continue to make movies with plots like that until more people complain.