I think it is Marriott fooling itself thinking we buy the notion that DL miles are just as good as AA miles.
Personally, I'd rather earn 5000 AA bonus miles on my next 5 Hyatt stays, which is on top of the FFN promo and the 500 regular miles. Why is Marriott being so uncompetitive? Even Sheraton added a AA sweetner of 1000 miles per stay on top of the FFN promo that they have and the points you normally earn. I have been Platinum four years in a row with MR, but I have only stayed 4 nights this year, and three of them were comped.