EK tickets are generally cheap, especially for 2 long-haul transit flights. Their audience are largely low income passengers, versus the relatively wealthy passengers on US airlines.
Whilst they may be filling seats, I can't see much margin at the moment. I always assumed that EK's strategy was to build the brand, build the loyalty whilst still expanding. Then at some point in the future hike the prices.
They are certainly spending huge sums of money on advertising to support the expansion. I'm sure that won't go on forever, and then may be added to the bottom line.
Have the US guys not had their pensions raided though?