That is all
If you read how Marcus earns status by frequently traveling Delta One or First, you quickly realize that Delta wants to award status to people who are less likely to use it. If you are buying D1 or F, the value of Diamond Medallion status is pretty pointless. I think in the Marcus scenario, there are only 6 main cabin trips (out of a total of 30 trips), which is when the free upgrades would be useful. Marcus already spent $33,600 on D1/F and puts $96K on the Delta Reserve card--do you think Marcus would have a problem spending an additional $4800 to buy 6 more F tickets (plus he could put the $96K in credit card spend on a 2% card and get $1960 cash back). The additional value of Diamond status is roughly $3000.
On the other hand, the typical road warrior would most likely end up in Sliver or Gold. These are the users who extract the greatest value out of the FF program and moving them down in the hierarchy makes it less likely to be able to get the free upgrades. If you get them to use redeemable miles (RDMs) or actual currency to upgrade because free upgrades is a crap shoot, Delta gets to generate some extra revenue (or reduce liabilities through the use of RDMs).
An alternative view is that the app market is similar to car parts or electrical devices and should be open to all vendors who can produce components that meet interface requirements.
I can argue either way, just as long as it is not annoying like the EU cookie banner. It would really sucky if I had to pick an app store every time I unlocked the screen.
We want to create puppets that pull their own strings. - Ann Marion