StingingVelvet: Yes really, one instantly becomes a part of culture and the other one does not (unless recognized by mass-media outlets).
Lou: A better analogy may be that deviant art owns his brothers pictures and shuts down and no one is able to ever see them again unless they have saved them and distribute them to others to enjoy. Really has nothing to do with the original artist / game developer - its all about who owns the rights to the content and what they are doing with it.
More or less, and the US constitution is very clear about the purpose of copyrights. What we really need is an addendum to take back those rights when companies fail to respect that they only get the rights for a limited time.
At this point, much of the art is lost before it is granted to the public domain. That's somewhat understandable when it's created by amateurs or when there's only one copy, but when it comes to things like movies, software and other mass media products, there's basically no excuse any more for that to happen.
What's worse is that only a fraction a round 1/7 to 1/8 of the known works were extended prior to the term being lengthened which suggests that a vocal minority has effectively deprived the public domain of most of the works, whether or not the creator really intended for that to happen.
Ultimately, we need a legal designation for orphanware and a mechanism for enforcing it. There's absolutely no reason why multibillion dollar corporations can't take better care of the culture they create.