A300Man,
I agree with you that Doha is more logical. They already have an interline and frequent flyer agreement with Qatar Airways and so they could always cooperate on the route. Qatar Airways wants 3 daily flights but only has rights for two on the other hand we have Bmi who have the rights a for a daily flight. They could both codeshare on each others' flights and QR will get their 3 daily flights and at the same time Bmi will have feed for their flights.
Another more important point is that Doha will be a hub for a certain "celestial grouping" next year or the one after at the latest. A european (non-Bmi) as well as two asian members of this "extraterrestrial coalition" are also eyeing Doha.