That's a question only answered anecdotally. Since you (or your wife!) place a priority on non-stops, try the objective test of listing all of Alaska Air's destinations (+ partners other than Delta) served non-stop from MSP. They can be counted on the fingers of one hand, in contrast to Delta's 100+.
Well, if you're like the poster you're referring to, I'd say he decided that as long as he's going to be near the bottom of the upgrade list anyway, as either an FO or AS elite, 25% extra RDM (AS MVP gets 50% bonus, DL FO gets 25%) and the ability to redeem on AA/BA/QF/CX/FJ (as well as the ability to earn full EQM on AA) was worth "outsourcing" the mileage plan and losing baggage fee waivers on DL.
At the GM/MVPG level, though, I'd think this was a tougher call, especially with a large chunk of flying on DL.