A horror-movie would not exist if normal human rationality was present. We would not follow the strange noise in the dark of old cellars. We would not tempt fate by trying to reclaim our valued belongings guarded by monstrosities. We would not try to face or fight these monsters. We would call the police.
In horror-movies we often have humans deprived of intelligence and social interaction skills. They seek out their sexually appealing counterparts and try to avoid evils, while at the same time developing their relationship. They often end up in terrible and horrible situations just because they are unable to realize the danger of their choices. Almost all of them have phones or access to internet, but no one is calling for help.