I hope I'm wrong, but I doubt you'll get much more of an answer than "It wouldn't sell enough in the eyes of the distributor in order to make it worth releasing in that format".
I've often been baffled by how many of the older winners of the Best Picture Academy Award are still not available on DVD. Best Picture!
Unfortunately it probably comes down to the person with the rights to the film, and the specifics involved with distributing it. Someone has to back that financially, and they need to know that they'll make a profit by releasing it, or at least not go broke.
Ok, I checked my source, and it appears that the industry has been doing some catch up lately in regards to Best Picture winning movies being released on DVD. Only four are not available as of today on DVD, but The Last Emperor was made in 1988! It's not so old that there wouldn't be any interest left in it. Who knows?
Last edited by dnooman; 08-25-2007 at 10:54 PM.
Reason: added last paragraph