I agree that many/most pax have no idea what machine they are riding. However, when my friend found the SQ experience in PE on a LHR~SIN~SYD was not what she had expected from the advertising, but the return legs were exactly what she expected: She learnt that the T7 was bad and the 380 Good. Same carrier, same cabin. Different experience. That does begin to add up for mature pax who have become more discerning and who share the information with their friends as an integral part of telling their holiday story and showing photographs. Junior pax with less money will always go for the cheapest.