Why is Philadelphia Restaurant Week Exclusive to Center City?

Restaurant Week is upon us again.  It’s a slow time of year for the restaurants and the idea of offering a 3 course meal for $35 seems to work well for business.  My only question is: Why is Philadelphia Restaurant Week exclusive to Center City?  If Center City extends all the way to 2nd and Chestnut, like with Amada, then why not go all the way to the river to include the waterfront restaurants, like La Veranda?  If 2nd and Chestnut is Center City, then what neighborhood is 1st and Chestnut, Chestnut and the river, etc?

I smell something fishy going on and it’s not coming from the Delaware.