For the whole time that I was active, the SS were hand entered on each book - which makes sense. You can have a WD #1 signed by Kirkman and Moore, either of them individually, by any number of TV actors etc. So while they can, by serial number, call up the data on any given book, there is no comprehensive way to gather the information and sort it into what would (presumably) be an entire new database. We used to joke that we (the SS nuts) would all do 12 hour shifts until they were all entered and then try to convince CGC to keep the database going from there. Trust me when I tell you that as long as I have been involved in the program, this issue has been hotly discussed.
As to the OP, it would be fantastic if the data were available, it would provide a lot of stability to a pretty illiquid market and it would give buyers and sellers a basic knowledge of the facts of supply of a particular signed book. CGC is not doing it out of spite, or because they don't care - it has always been a business decision for them. How does it increase their bottom line if they allocate resources to this issue? It doesn't. And that has pretty much always been the end of the story.