FF2
No surprises to me in the abrupt closure of Belfast by BA/IAG. They are simply not interested in anything that doesn'y serve LHR. They will get bad press in NI, but as they will still have former bmi LHR routes their business customers will be happy, so they have no issue. They are not interested in any other market from NI. Period.
The retention of some mainland UK routes is I suspect being done as they can cope better with reduced staff numbers (as staff leave in advance of closure). Also, the backlash in the mainland media will be less if routes are kept open here; the Belfast closure will get limited mainland coverage after the initial announcement.
BA has long ceased to be the UK national carrier in anything but name - it is London Airways, pure and simple.
MD