I think it's 100% marketing, they made a new card that outperformed the previous gen by 30% so to fluff that up they created a new aa technique that ran wayyyyyy better on the new hardware (or conversely much worse on the previous gen, which isn't inconceivable considering nvidias past actions) to make the performance divide much larger.
The fact that it isn't particularly good would give credence to the idea
The fact that it isn't particularly good would give credence to the idea