Sorry Betty Girl I was being sarcastic, the medium of a forum is perhaps not the best for expressing such subtleties.
The point is that with the current WW agreement there is no way that BA will pay out for a bidding system. Those who are trying to persuade themselves that it would be in BA's interests to make their lives easier without giving anything up are being foolish.
BA has a rostering system that works. If the cabin crew want a bid system for LH they will have to "buy" it by giving up something that will save BA an equivalent amount of money.