Originally Posted by
pinniped
(Disclaimer: I don't know the nuances of all of the Asian FFP's. If there's a compelling reason why, say, an ANA flier would accumulate on US instead of ANA, I'm not aware of it.)
Yes: not-so-frequent flyers or those that travel routes that can't be serviced by just one airline. In those situations, one must broaden routings to the alliance level and then bank all miles in one FF program. I am such a traveler and so far have chosen to bank all Star Alliance miles with US Airways... though since the recent UA/CO merger, I am reviewing this decision.