To be fair, a lot of discounted domestic F fares these days are likely cheaper than the Y/B/M fares of yesteryear, and while not refundable, can still be changed without a change fee.
YMB fares are still more than the discounted F, that is one of the challenges here. Someone who buys tickets 3 -5 days out usually pays more than half the F cabin. I get DL wanting to take care of those people, but this is another one of the issues they created with FCM. They want to correct it by shrinking the elite pool but as a DM on those type of fares I don't see how fewer DMs helps me since there still are no seats in F to UPG.