Emirates has some of the highest revenue and cost numbers per average seat kilometre [0]. It's also subsidised to a large extent by the UAE [1]. I don't find the word "rich" to be very descriptive, but "high end" could easily apply in this circumstance.
I don't necessarily disagree with the high end. But looking at the CASK it's worth noting that they're almost exclusively long-distance flights. I'd like to see the graph from [0] split into long-haul and others. Currently they've got Emirates flying 10+ hours on the same graph as EasyJet doing 30min in Europe. Same for Quantas which does domestic 1h flights as well as international Dubai, or west coast US but is in one bar only. I know these are normalised per kilometer in theory, but there's a threshold when you need 2x the crew, can't really go without entertainment system, etc.
Or specifically why I didn't say rich is that it's not like you have a lot of choice flying long-haul over middle east. You're likely to get a stop-over in Dubai and if you're flying One World, you're likely to have an Emirates code share.
Of the ME3 Qatar is the one that's in oneworld. Though it is Emirates who usually codeshares with Qantas because of their separate partnership agreement.
[0]: http://www.oliverwyman.com/content/dam/oliver-wyman/global/e... [1]: http://www.prnewswire.com/news-releases/emirates-confirms-bi...