Answer:
People love being at home watching a movie where you never know what's coming next. Some really enjoy the fear responses and the thrill that comes from watching horror. It gives the audience novel experiences, a special type of feeling they wouldn't get in real life. Some people are risk-seekers and love seeing content that acts on that impulse for them. There are many reasons a person may like the horror genre, but the main one I think is that people love stimulating their senses in a way that frightens them as they never will in day-to-day life.