Norwegians short haul operations around Europe and esotfrom/to Scandinavian does very well and is profitable.
The problem at LGW is lack of slots, if you are up against easy with say 4 flights a day to AGP and you only have one, they can price against that rotation denying you a profit, whilst hiking the the price of the other rotations that you don't compete with.
The problem in the North of England is somewhat different, there is over capacity on many routes so yields are lower to start with, this part of the UK is very very price sensitive on bucket & spades routes.
People will readily fly at very unsocial hours to save a £5 a head, which is another £5 to spend on. Booze in the resort, many know that Ryanair is crap, but they can put up with being treated like dirt if they can save £20 a head ( or think they can) !!
75% of all Thomas Cooks bogus holiday sickness claim come from Manchester/Merseyside, there is a mind set in this part of the world for many that us best summed up in the saying " they know the price of everything and the value of nothing" so Norwegians far superior product offering if costing even a few £s more will not find enough takers.