They are probably not on dvd because the last scans done were done for dvd.
Lucas has to pay money to have the negatives rescanned at a higher resolution than 1080, which is what the dvds were done at for star wars and indy.
Sure they were able to have HD broadcasts but the current masters are not at blu ray quality.
But is not this the same george lucas that made the nonsensical assertion years ago that dvd was as good as film?
Because Lucas says it must be true. If any other individual said it you would doubt their sanity, expecially a director who has worked with film.
4k is the lowest exceptable point when scanning 35mm film and much higher resolution scans are being done today. So a 1080 master downcompressed to 480i certianly does not past muster when compared against even a theatrical print much less a first or second generation master or the negative itself.
I shot first already quoted it as his sig but i will copy lucas claim here for all to see and read just how much of an ass it makes him sound.
"The other versions will disappear. Even the 35 million tapes of Star Wars out there won't last more than 30 or 40 years. A hundred years from now, the only version of the movie that anyone will remember will be the DVD version [of the Special Edition], and you'll be able to project it on a 20' by 40' screen with perfect quality. I think it's the director's prerogative, not the studio's to go back and reinvent a movie."