yeah wow all these posts...
my 2 cents
I tend to think of it as the "home" carrier's rules applies above alliance ones. So QF can determine what happens to their pax but needs to follow alliance rules for their OW and partner pax (eg: an OWS or OWE can also access your QF lounge per those rules, or I think an AAdmirals Club member can under a separate reciprocal agreement). I do agree that a QF status pax is treated differently at QF lounges for access requirements but it kind of makes sense to me.
I mean remember lounge use is charged for and I think this has a great bearing on it. If I am flying EK in F or J but on a QF codeshare, it is still EK who gets charged, now I would imagine the partner operating carrier would WANT to stipulate that if I'm going to bring a guest in and they get charged for it, it should be a guest they are getting revenue for (ie: flying on that flight). Same with NF, FJ, SB etc.
Under the OW agreement, which is totally separate to other partners, QF has an obligation to the partner airlines customers (by status or CoS) to sup0ply access, but they would also charge that back to that carrier (eg: CX, BA etc). I'm not quite sure how that works revenue and charging wise, but I suspect it is a requirement of membership to wear those charges, and in theory it probably all comes out in the wash over time, or they may even have intra-alliance set rates and the like to cover it.
This is why, a oneworld emerald (say AA elite) flying on EK couldn't get in under their status (non oneworld operated flight) but could under the CoS if they flew J or F. It is also why AA can deny their elites access to their domestic clubs but allow other OWS/OWE in - in essence AA is doing exactly what QF is doing with their own pax in my view.
I had this applied back in December when I met someone at random at security at MEL flying CX. I was on EK (QF code). tried to guest into F lounge but knocked back as they weren't on the EK flight. It's what I half expected but didn't hurt to ask.
it may seem very confusing and contradictory to many but when I think of it from the "other side" and remember to separate that a passenger seeking lounge entry is coming in in a number of ways - as a QF customer with their own access rights, a partner carrier's passenger, an oneworld status customer, a oneworld premium (ie: CoS) customer) etc thus each have separate definitions for how they need to be handled.