Bose is correct - it is a commercial market. We may all wish otherwise (including Bose I suspect), but that is the reality.
As with any commercial market supply and demand has its influence.
I recall when Bournemouth hiked its fees it became a grave for GA. They realised they could slot GA in with the commercial traffic (and all at marginal cost because their fixed costs remained the same) and GA returned.
STM have a problem in that the amount of commercial traffic is small and there are the MOD fees to be paid as well.