Respectfully, while I understand your frustration, I don't see what is unfair about any of this. It may or may not prove to be bad business for BA, but I don't think it's reasonable to think that BA should serve you as comprehensively as it serves those in its home market from a 'fairness' perspective.

Logically, based in HK, CX would be where you would most likely put your loyalties. BA would no doubt like your business, and logically they need to make the scheme more attractive to the 'non-obvious' customers than the obvious ones, but if they choose not to I think the best option is to move on to whoever serves you better.