I don't think it is, because I guess I am obsessed with horror movies. A fixation with horror movies could be attributed to a number of factors. If horror movies cause fear, then the "obsession" may be more of an addiction to the resulting adrenaline rush that accompanies said fear. It's comparable to being obsessed with riding thrill rides, such as roller coasters.
Watching horror movies may also contribute to the natural human tendency to have a fascination with mortality. Some allow the viewer to feel exposed to the idea of death, as well as feel some of the intense emotion associated with it, without actually having to experience it. Again, the same defying-death mentality also associated with thrill seekers.
I never was. They are, after all , just movies. When I saw King Tutankhamen at the Philadelphia Museum of Natural History, I was 10 years old. Seeing the flesh and bones that were once a great king kept me awake for two weeks.
Watching horror movies may also contribute to the natural human tendency to have a fascination with mortality. Some allow the viewer to feel exposed to the idea of death, as well as feel some of the intense emotion associated with it, without actually having to experience it. Again, the same defying-death mentality also associated with thrill seekers.