Not sure where your numbers come from since you didn't post any sources. But my reading of the DL forum on FT the past few months has indicated that not just FT'ers are stopping short of 125K MQM. Don't have the time or desire to weed through and find the more-than-one post about friends and colleagues who don't even know FT exists doing the same thing.
Frequent travelers who are not on FT are usually pretty savvy too. I think you are greatly underestimating your numbers.
Even so, if the goal was to keep the flyers beyond 75k and up to 125k, then Delta gets what it wanted even if someone chooses to stop short of the Diamond level.