The jump in quality is less significant for dvd to blu than it was vhs to dvd. I know plenty of people, young AND old, who claim they can't see the difference at all. So in short that's probably why. Star Wars would be selling even more like hotcakes if more people had made the jump... also VCR tapes were out of the general market by the time Star Wars was on DVD; up until this recent recall, people could still easily pick up the saga on DVD.

Pardon the "Man-who" testimonial but I was hoping it would prove my point...