I guess Delta or any other carrier is not looking out for traveler with a profile like yours. They are in the mass transportation market where they have to fill as much seats as possible, as reliable and predictable as possible to operate with profit. Pax with booking patterns like yours (or mine) are just good to fill up the last few seats at the last minute... a nice bonus.

and the one thing is clear, ticket prices are the one and most important thing deciding the load quota in the back of the plane. For the pointy end, (actually both ends are more or less pointy...) I think next to price you have corporate agreements, schedule and route network/convenient connections which determines how successful (means how well booked) a flight is.

very little has to do with ancillary services on the ground.