Rockhopper - airlines don't normally pull routes which are making money. If a route or set of routes are not covering the fixed costs of the aircraft and crew and you have a better bet to deploy the asset in a way where it can cover its costs, you do so. If you have two potential sets of routes of which both make money and cover full costs but only one aircraft, you go and get another aircraft as it will enhance your overall company profitability. It's not as though the desert parking lots are exactly devoid of SF340s.
The likelihood is that the routes were not covering the costs of the aircraft and crew, and better deployment for the asset came along. It makes no sense to increase the fleet to keep flying routes which don't make money.