Married segment focuses much more heavily in Qatar's revenue policy as they operate a major spoke and hub network where most (90%?) of their passengers journeys are transiting their Doha hub with a small proportion of traffic originating or terminating at Doha, and notably the originating traffic is not so price sensitive and there's usually a price premium attached because the local Qatari market will pay it.

Whilst the traditional US carriers do have a proportion of journeys that transit their hubs, it's a much smaller proportion of journeys and hence revenue strategy is just to join together individual sectors and price accordingly, and hence married segments is not a focus in their business models.