Market development requires competitive equipment. We can't develop a market with inferior equipment and high costs. We are sitting ducks for Jet Blue and even Southwest Airlines.
Delta management intends to acquire market share and then constrain capacity until it is profitable.
Someone used the phrase "MBA death spiral." It is apt with the use of 50 seat RJ's to develop markets with too few seats to spread the fuel and trip costs amongst. The E175 is a mainline equivalent. Really, what we need is to fill the scope gap with mainline equipment operated by new hire mainline pilots at reasonable (market) costs.