Yes that is exactly the spin that Teesside, Blackpool, Manston, Prestwick etc used when their passengers went up and up - but now look!! It's not about whether somebody or bodies are 'doing something right' it is about whether what they are doing is sustainable and makes money. Newquay airport, for example could charge £0 to fly to Spain and guess what their passenger numbers would rocket up too! Why has the national flag carrier of Ireland tried DUB twice and not hung around? Why has Belfast been tried by numerous airlines and ended? Why have RYR and EZY come and gone - the answer is simple; the catchment population is small. All airports and their rich owners will do deals and so the catchment population is all important because after the deals are finished airports will have to rely on the natural underlying demand.
You would need to show proof that BE flights from DSA [pro rata] are dearer than the others you mention as I have huge doubt about that. Are flights to CDG etc full on the 100+ seater?
Those multi million passenger airports can offer 'cheap' flights because they have the demand through having a much bigger population catchment and hence natural underlying demand. Like I say it's Teesside all over again. I remember the whoops of joy when BMI baby were flying all over the place - but after the subsidy were those routes making a profit using the natural demand of the catchment population?
I would love to see that BE deal - it must be eye watering!
Meanwhile Yorkshire suffers through the subsidised infighting.