Ultimately they need to fill whatever airplane they put on a route to make it profitable. If you can fill a 76 seat airplane you can fill a 118 seat airplane with proper marketing and reliable service. Especially when you consider the fleet commonality and the cost to operate another 737 vs a new fleet type. LCCs are starting routes with 160+ seat jets and yet we are determined to use crappy, delayed, and incompetent regionals to build new markets. We don't need a new fleet type that will do nothing but complicate our operation. Let the 737's and Airbus's do the lifting.

There is zero reason to give on scope. Not on weight and not on passengers. The 175, in my eyes, isn't a regional aircraft. We have 3d printing and an increased use of composite materials coming that will lower the weights of these jets.