That's really silly. One of the main reasons so many people cling to copyright is so that they can (in their minds) maximize their revenue. The company that developed the game has not and probably never will make any money from it, so from this stand point, not allowing it to be copied isn't helping that company benefit monetarily at all.
Also as far as value goes, a work gains value the more it is spread and enjoyed by people. Value is something that people give to things, whether it be an object, book, video game, etc. It doesn't have it intrinsically. An unpublished manuscript to a book that's locked up in a safe some place doesn't have all that much value to people who don't know about its existence, does it?
Having the game data copied doesn't take away from the physicality of the game machine. That game is a one-of-a-kind, unique, physical object that no amount of digital copying could ever hope to rob away from it.
So if we really have to wait 100 or so years from now for the game to finally enter the public domain, and within that time span it turns out that the data has decayed and it utterly unrecoverable, then we will have lost a unique piece of video game culture forever, and it will be solely because of that one man's stubbornness in adhering to a field of law that is losing relevance with each passing day.
I could go on and on, but I'll leave it at that.