We've ran out of stone.
Our supplier of those precious stone blocks, so vital to building our castles, has been unable to enter their quarries for several days (they have some silly excuse about digging too deep and releasing an ancient evil). Our reserve of stone has been steadily depleting. Without stone, as you know, a castle simply can't be built. We at Empire Avenue have looked at all the possible alternatives. We've considered straw castles and wood castles but both have proven structurally unsound in light breezes. An attempt at a glass castle failed sharply. Frankly, we are out of options.
It is with our profound apologies that we must announce that production on new castles will soon cease. Get one while you still can. As of September 5th the drawbridge will close for the final time.
If you already own a castle or don't really care to own one (after all they are a bit drafty) rest assured that our clever engineers are hard at work designing possible replacements. We are sure an idea of sufficient coolness will surface in the near future.
Oh, and a clarification: If you already own a Castle, it won't vanish or expire (the stone we did use is really really strong); You'll continue to receive the benefit.