: Which goes back to my initial point: "[even in a well-conceptualized
: fictional universe] storytellers can run out of good ideas. It may also be
: possible for bad storytellers to close off options for storytellers in the
: future."

If you don't close off options for storytelling nothing will have finality. You can always open a window when you close a door, you can even open two or three and another door to go with them, but if you don't close a door now and then the wind of pointlessness will blow through the house that is your plot, and that wind is a cold one.
(I'm not sure how we got onto this from weapon designs.)