Flights to LCY gives connection options to GLA, EDI and ABZ. I for one would be happy with that as I need to travel to ABZ, for example, and at the moment that means 3 flights XRY-MAD-LHR-ABZ; so I would be happy to drive an extra 30 mins to take the flight from SVQ to LCY and then up to ABZ.
There may be demand for a MAN or BRS service, but at least this is a start...