Now I get it. The genius of American Horror Story has been revealed, altho it was out in the open all along for anyone to see. The story isn't about the family living in the haunted house. American Horror Story is about the haunted house. The family is just the latest chapter in the saga. Welcome to Hotel California 2011.
It wasn't until the final family member died that it all became clear. How would the story live on with everyone dead? You write a new chapter with new owners. Genius! I mean if you try to follow the Harmon Family's story, you've pretty much come to a dead end (no pun intended). Now, AHS has a clean slate for the writers to work with next season and they're armed with the same cast as ghosts, all with different agendas. Win/win.
Best sci-fi/horror/whatever since Hitchcock and Serling.