I don't see what's wrong with cross-subsidisation when they are part of the same group?
Wouldn't Toyota and Lexus do the same, the hotel chains that have multiple levels of hotels and so on?
QANTAS Mainline is just one arm of the QANTAS Group, although I don't like how the QANTAS brand has been left to the dogs a bit, I don't see why cross-subsidisation is bad?