I don't think that flights like the ones we are talking about mainly target the VFR crowd. I also doubt that the majority of passengers are families of 3 or 4.
Anyway, as it is impossible to offer Ryanair-style fares from regional airports on 30 or 50 seaters, the discussion is and complaints to that effect are moot. Either Waterford is able to fill a 30 seater at perfectly reasonable fares or the end of scheduled services from Waterford is nigh again.