Skipness 1E, there are many reasons for why an airline drops flying between two airports after such a short time, but contrary to many other airlines Norwegian tries and tests new routes all the time. Many of them can't fly, but there are some of them that can fly on their own. Over time Norwegian have developed new markets, but they have also big failures. You Skipness 1E seems to concentrate on failures, while other of us looks at successes - the glass is half empty or the glass is half full.
One thing is for certain, Norwegian try to develope the industry, not preserve it like some of the dinosaurs do.