That would make me sad, the boxes and the super-deep CF add character and variety to the park. I can't stand places like Turner Field that have one, long, evenly-curved, boring OF wall.
But there's a more practical consideration as well; the fanbase likes sitting out there, and they don't want to losing seating. The Boxes are generally at least mostly full even when a scrub team is in town and the rest of the stadium has fields of empty seats.