I, for one, am not a huge fan of horror films. Life is disgusting and horrible enough for me on a day to day basis, thank you very much. Who needs some slasher thriller when you can turn on the news?
That being said, I do appreciate the basic archetype of the genre's structure.
Group of young, impressionable people want to have a good time, preferably far away from parental supervision. They find such a place, only to discover that it is infested with leprechauns who eat people/knife wielding masked deadmen/dolls/or in the case of "Cabin in the Woods," every single monster/demon/ghoul ever.