Thinking about the end of the world

I watched what was quite probably the worst film I've ever seen on Saturday night. It was called 2012: Ice Age. You can guess what the film is about from the title, and it got me thinking. Why are so obsessed with the end of the world or the end of society? It seems odd that we enjoy reading about or watching the human race die off. Heck, I enjoy writing about it, but instead of earthquakes or aliens I have gods squashing people. Maybe we're all mad...maybe the Mayans are right and the world is going to end and we're all somehow attuned to it and are preparing ourselves. Or maybe it's just a phase.
Or are we already living in a dystopia?