Arguments about when it may happen notwithstanding, Trevor Longino is absolutely right.
It boils down to the difference between a hobbyist and an enthusiast. Someone who games as a hobby is glad they can play Diablo 3 now (assuming the servers are up, but I digress...), and once they are done, they're done. But gaming enthusiasts worry about things hobbyists never give a second thought, like a day will eventually come when a game like Diablo 3 is completely lost to everyone.
When you go to a museum, do you look at hieroglyphics and ancient art for their aesthetic value? Maybe a few people do, but it's not why I go - seeing things like that first-hand gives those of us with a fascination for history a clear picture of what came before; it gives you insight into the very culture of the time. It ceases to be a singular simplistic drawing or sculpture and becomes part of what teaches us history. Together with other cultural artifacts one can draw a near-complete picture of that era from what individually amount to very little. A gaming enthusiast views old interactive entertainment in much the same way, and the idea of a landmark game one day being lost to the ages is a sad thought. This is a part of our history and our culture after all.
“The greatness of a nation and its moral progress can be judged by the way its animals are treated.”
- Mahatma Gandhi