Pretty much. Dividend Miles is not a generous program at all compared to M+, either on the earning side or the redemption side. For the time being, if you don't count upgrades, M+ elite members are rewarded better for flying US than are US' elite.

And as US decreases seat pitch in F and removes seats from the F cabins, that's not much of a reason. I guess the flip side is that as they reduce the quality of their program, there are fewer elites to upgrade.