It's not as if they didn't try. BA flew to JFK with an L1011 from Glasgow, then a 763, moved it to Newark, back to JFK, changed it to a 757, extended it to Boston, dropped Boston, moved back to a 763 summer only and then gave up. Basically every pax on the Glasgow flight was potentially one less ona London service. Go where the money is chaps.
Now if Loganair bought a 767 on the BA franchise.....