If you're running a high-body-count-low-property-damage Post-Apocalyptic campaign (like The Walking Dead or The Stand), would you rather set it in your local vicinity, or would you rather run it anywhere but your local area? I can think of advantages to both approaches, but my gut tells me I'd rather avoid the annoying "I know more about the area than you do" thing from players. And really, if the player is right, then he's right, and there doesn't seem to be much sense running a campaign set in a place where the players can know more about the setting than you do.