The article focuses on games that were never released or never even completed. It could be argued that those (unlike Pac-Man) did not contribute to cultural heritage. This is obviously not to say that their preservation is unimportant; I just think it should be compared more to unfinished/unpublished works of art, not the statue of David. It's more like The Salmon of Doubt than it is The Hitchhiker’s Guide to the Galaxy.