Wow, astonishing devaluation by QF/BA! As lounges are renovated they are being rebranded as Galleries (often no better than the same lounge as Terraces but with newer furniture), so in a few years there will only be Galleries and 3rd party lounges. I guess BA pulled a Concorde on QF! Presumably the lounge access fee paid by QF is too low, hence this is BA's response to that little negotiation.
As others have emphatically stated on this thread, BA did allow QP card access to the T5 Galleries lounges until recently; interesting stealth change. Gotta love Oneworld, it is such a happy alliance. I'm slowly switching to LH in part due to this BA attitude.