Its mainly due to the cost of doing work in the northeast...unions, cost of construction, rent/ real estate costs, etc. There is an article somewhere that talks about the chain, Wawa and how the northeast is a costly place ro open stores.
Sometimes you will see a store like Old Navy or some other crappy chain store opened up in a high rent area of a city. People wonder how they can afford to stay open. Sometimes that particular location will take one for the team so to speak, barely making ends meet in order to maintain a brand image that people can see and will remember. Places like fast food are tough, and risky to take a chance on, especially a place like Chick-Fil-A where they are sticking to their high ground with regard ro being closed on Sunday. That is a huge loss of business if you are paying triple net on your high rent lease.