You know, now that I'm thinking about it, it does make sense. For instance, in HKG there are the 2 CX lounges as well as a QF/BA Lounge. If J or F bp were all that were required to enter any oneworld lounge, then what's keeping that QF/BA passenger from using the nicer CX lounge at HKG? I suppose by limiting cross-use of lounges to those with status, it's a form of capacity control. Nothing's more irritating then a full lounge.