I wouldnt call them niche routes, I would say it would work better for a niche carrier though. Focused on regional prop routes, Rather then the likes of EZY with an Airbus.
As we have gone over those airlines are few and far between at the moment, The thing is if anyone was interested you think they would get going soon enough. You want to be selling your spring and summer tickets now dont you? Get yourself embedded for the leaner winter months that follow.