Roleplaying games are a deeper subject than many want to contemplate. They don't want anything to get in the way of their play, even if it's a cogent analysis of the game they're playing. I refer to this as the "I don't need no instructions to know how to rock!" school of Anti-Intellectualism.
And this is why you don't hear more about what should rightfully be the greatest, most bitterly contested philosophical disagreement in the realm: "Who controls the story?"
If you think creating your own campaign world from scratch is too much of a hassle, consider the alternative.
When running a game, the GM's aim should not be fair play, but fun play. The GM and players both need to keep this in mind.
As the title says, nothing starts from nothing. If there's a big problem, it was set in motion by a smaller problem, and that started from a single event. Walk it back and determine what that event was, and you've got a good start writing your next adventure.
