DNATA does help their profits in all airlines subsidaries do, however more capacity and lower fares are the future, even Airbus said recently (at 10,000th aircraft, an A350) that its inevitable airlines will require more A380s. Many years (if ever?) before LHR has more slots and other hubs will soon be at limits too.
I too had wondered about the yield that EK obtains through its use of wide bodies. As others have pointed out elsewhere, it is the easiest thing in the world to get bums on seats, it is very considerably harder to get them if you intend charging a price that delivers a contribution/generates free cash flow.
