At one point the Age of Empires developers considered adding natural disasters to the game. But it wasn't consistent with their presentation of an inviting, sunshine-drenched world or their player-centric design philosophies.

(On a related note, there's an anecdote in my book from Bruce Shelley about Bill Gates trying the game and asking if it's meant to be educational -- it wasn't, and Shelley had a great explanation for why.)