But let's say they have claimed it, and we assume average yield versus the competition. Now you have a problem with your claim that ATL, DTW, and MSP are about the product. It doesn't make sense that the same product can command a premium in some locations but not others, assuming everything else is equal. The elephant in the room is that it's not equal.
1. The hubs you mention do not consist solely on local traffic. As it's been pointed out previously both DTW and MSP have equal, or smaller local traffic bases than hubs that are controlled by AA like CLT, PHL or DFW, or UA's DEN or IAH operations. So if the local traffic bases are similar- and they are all fortress hubs- again why is DL reporting superior returns? All three legacy carriers fight for the coasts, and the competition at ORD doesn't explain a 25% lower operating profit for UA and AA. IMHO the DTW and MSP hubs don't explain the higher profits.
2. My experience in the industry taught me that CONNECTING traffic is key to superior profits. There's only so much local traffic at a hub, and it's usually not enough to guarantee profitability, no matter how strong the local yield is.
Customers who live in the midwest for example have multiple options to travel from SDF, CMH, CLE, MKE, BHM, or LIT. They have to connect to most cities. They have a choice, as no carrier has a hub-like grip over local traffic.
Connecting traffic is a very important component of any airlines revenue generation.
And reputation and service are part of the consumer decision matrix.
Why does a customer in IND for example chose a particular carrier between IND and PDX for example? They have multiple options.
IMHO, DL is winning (for the moment at least) the battle for the connecting traffic from non-hub cities. While you don't seem to agree, I contend that DL's service reputation and reliablity are giving them a revenue advantage. And it is an advantage that they have spent the last 10 years working on- since the DL/NW merger.
It's a very slight advantage- but it adds up when you carry 14 million passengers in a month.
I would respectfully suggest, that DL's overall product delivery is moving market share from non-hub cities they don't control. The HUBS are equal for this discussion. - but service delivery and customer perception are NOT. I realize you don't acknowledge that the DL brand or service can influence traffic.
However- I know brand does make a difference from previous personal experience as an airline sales manager. When I was in the industry, AA had a superior product in every sense- cleaner planes, nicer airports, happier employees- a generally better reputation among high yield business travelers. Even though we all flew 727-200's and DC-10's.
Where I worked- we had to overcome that perception and reality via pricing. The corporate deals I cut had to be more price aggressive to overcome AA and their service advantage. Fang (Mr Crandall) was kicking our butt.
We made money too- but it was by cutting costs; the lower costs, (and lower resulting service level) made up for our lower yields.
The same problem took place from the spoke cities- passengers perceived lower service levels, and needed price stimulation to move purchasing decisions.
Now the tables have turned IMO- AA and to a lesser extent, UA are chasing DL. And my marketing/sales friend at AA and UA admit this privately to me. (they can because I'm now out of the industry)