Closing off the week on online previews for GTAV, IGN has posted an interview they conducted last month with Rockstar's VP of Creative and GTA writer Dan Houser.
Doing other cities just didn't seem appealing. Doing small towns is very appealing. There's a bunch of small towns and villages and whatnot in there to discover and play around in. Doing other cities, though, felt like it was going to create problems we didn't need. It wasn't going to add to the experience. Of course you could do a game with a bunch of cities now that could be pretty interesting, but we didn't think that was going to be this game. This map is going to be spectacular to people when they start exploring and playing around with it.
Read the rest of the interview at IGN