What they mean is the only way to play these games is emulation instead of being able to purchase them from the company that owns the rights. That's bad because many people either do no know about emulation, do not know how to emulate, don't want to figure out how to emulate, don't want to involve themselves in legal gray areas (downloading ROMs is illegal afterall) etc... Basically, the companies that have the rights to these games are just squatting on them and not ever rereleasing them again. Those people above can never or will never experience those games. Some people want to just pay the company and play an old game that they heard about so they can't. As far as preservation goes, the archivists have that covered but there just isn't a solution for the average Joe to play older games that are no longer sold physically or digitally.
In the article it mentions emulation as the only method to play some games. I mean, that's a good thing right? Digital Media can be copied and shared over and over. Physical media can get lost, destroyed, hoarded. More work needs to be put into perfecting emulation software, and we need to ensure there is a backup of every game ever released.
save