Sony has thought through this pretty carefully. Sony is trying to get as much Blu-ray content of high quality out as quickly as possible but still make money. I praise them for the former and cannot blame them for the latter.
This is a title that was widely distributed on other formats throughout the years. It is not a title that particularly requires Blu-ray treatment in the eyes of many buyers.
While I personally think that virtually everything deserves a Blu-ray transfer, I also find myself deciding to stay with an LD or DVD for a title that doesn't seem to make that much difference to me. My "new rule" has become to watch many catalog titles on LD or DVD to decide if I think it is really worth it to go with a Blu-ray. I go with a new Blu-ray a lot of the time.
As Good As It Gets would not, for me, merit a Blu-ray upgrade. Others will disagree.
Apparently Sony has concluded that the sales would not be high in a normal release. I think we have to put some trust in them. This is Sony, not Universal, they have pretty good record.
I have bought most of the Twilight Time Blu-rays so far. I am thrilled to get a title like The Egyptian. Picnic is one of my favorites, I actually bought a second copy just to have a spare of this excellent movie. I am glad that Sony and Fox are letting Twilight Time distribute these titles which, however wonderful they are as films, just would not sell enough to warrant a general release.