Equally though on the Stansted route Newcastle had better links to Gatwick and Heathrow which offer far more connections and are both better located for London.
I'd imagine most pax from Newcastle transit through to another destination from LHR and LGW especially with the BE/BA codeshares.
Jet2 didn't want the route, easyjet couldn't make it pay.
Carlisle is a slightly different proposition as it has zero links to anywhere to compete with