The cruise idea makes sense, but it seems that isn't what Oneworld had in mind for the rule change -- otherwise it wouldn't be restricted to SWP origin only! The bulk of such cruise pax would presumably be from US & Europe, not Australia. This particular rule change is intriguing, both that it happened and that it is limited to such a niche market. Presumably the OWE rules are designed to force buying a different (higher) fare if unable to meet the conditions, and using RTW to fly to a cruise appeared to be one of the prohibited activities (and still is, except for SWP). But then SWP has always had better rules than the other points of origin, for whatever reason (hard to believe that QF insisted on better terms than elsewhere in OW).