I think it would be nice if we left Brexit and its role in bmi's demise off this thread and maybe parked it somewhere better suited to strong opinions (OMNI).
Some of what they flew was useful, some profitable. Maybe they had too many aircraft, or aircraft too expensive to operate, and couldn't get the right routes to survive.
I'm finding it hard to believe that BRS hasn't demonstrated enough demand for routes to FRA and MUC for LH (Regional) to operate it well. Whether they have the fleet to do that is another question. Routes like BRS-HAM and BRS-DUS, which each ran 6x weekly and collectively carried only 2,000 passengers a month seem to have been closer to follies