These days it's probably not necessary. Starbucks doesn't franchise and this allows them to do things that make more sense for Starbucks as a whole as it would make for any single location, for instance, the notorious Starbucks across the street from another Starbucks that Lewis Black ranted about. However, it made a lot more sense in the early days of McDonalds because of the sheer organizational complexity of employing people in every medium-sized-and-up town in the United States, and now, franchise holders are an established and vested interest that the company needs to keep happy.