I don't think that such a large airport with its attendant investment can succeed on the basis of GA activity!
A shame really that such an increasingly excellent facility just doesn't have the catchment and access enjoyed by Southampton with its lesser facilities.
The leisure market, served primarily by low cost operators, just does not generate the required revenue. Teesside, Docaster, Blackpool, Coventry, Cardiff etc etc all in the same boat.
Just too many airports on this small island??
Helen