[TylerE]

It's a lot more complex then that. Arguably, the single root cause of Concorde being retired was the Flight 4590 crash in 2000, which hurt passenger numbers quite a bit.

Operations were further hamstrung by the very small fleet size. There are certain things that just have to be done to get an aircraft commercially viable (spare parts inventory for instance), and when you have a fleet of only 20, that will cost much more per aircraft than supporting something super-common like a 737.

It's also worth noting that Richard Brason, at least, thought Concorde was still viable, and made offers for the BA Fleet as high as £5m/aircraft, but was refused, at least partially because Airbus was unwilling to offer continued support.