I too felt QR would be the first to buckle, perhaps OneWorld is propping them.
QR's membership of OW isn't propping the route up. It's membership is part of what is making the route increasingly more popular. BA has a high number of top and mid tier exec card members in and around the EDI catchment area. A ever increasing number of these card holders are using QR to fly to the Middle East, India and Asia. Membership of OW mean exec card holders accrue tier and avios points and often paying around the same if not less for the ticket.