I'd imagine the IOM-BHD route should have been successful, the Isle of Man needs these routes.
The the ludicrous decision to get easyjet onto the iom - bfs route will have taken the profit away from eastern, and as expected they pulled off which probably explains why they ditched the other Belfast routes. (Can't speak for NCL however)
this mwans Belfast and the IOM now go from severa flights a day to 2 a week ...