Horror is like comedy. Woody Allen's comedy is going to be very different from Ben Stiller's comedy which is going to be different from Adam Sandler's comedy which is going to be different from Judd Apatow's comedy. They're all comedy, but they're all very different types and you can enjoy all of them. Horror is the same way.
I think that horror films have a very direct relationship to the time in which they're made. The films that really strike a film with the public are very often reflecting something that everyone, consciously or unconsciously feeling - atomic age, post 9-11, post Iraq war; it's hard to predict what people are going to be afraid of.