I also agree with the sentiments about Norwegian. It is no good simply flooding already saturated routes. It helps no one. Not the new entrants, the incumbents or the airport.
But surely as a base, Norwegian would be one of these 'new' entrants? (yes they already serve MAN, but, as a base, it would be a different prospect to what they are now.)
Also, given the amount of sun routes, are Ryanair and easyjet not 'flooding markets' also? Quite a protectionist view to hold really.
Also, who is to say Norwegian would purely aim at 'saturated markets', and, what are the 'saturated markets'?
Las Palmas, for the size of the island and offering, is served significantly less than TFS/ACE for example?
There are plenty of destinations, that, MAN sees as underserved that Norwegian do serve, so could quite happily co-exist with the MAN incumbents. If EZY/RYR don't want to serve those routes, then frankly, let someone in that will.
Could there be slight over-capacity to places like TFS/PMI/AGP? Yes, but, its not like its never happened before?