Aviation Week has a photo of 5 decent looking little regional jetliners parked out in the desert, the traditional place to store unneeded aircraft. The dry sunny weather and lack of rain and snow preserves the aircraft for years. These are small, 44 seat models, with a lot of flying hours left in them. Apparently little jets don't make enough money to keep themselves flying. Regular airliners, say a Boeing 727, will seat 150, and big airliners go up to 500 seats.
The small regional jets were developed and sold because passengers prefer jet aircraft and view propeller driven aircraft as old fashioned, noisy and high vibration. But, apparently the very small jets don't earn their keep.
Aviation Week didn't say just why the small jets are getting scrapped. Could be the propeller driven planes are sufficiently cheaper to operate than jets. Could be air service to small air ports is being abandoned, leaving the passengers to drive to a larger airport. Could be the small airports are actually big enough to land bigger jets, and the air lines are going for larger aircraft that can serve both small airports and larger ones too.