Someone in that reddit discussion was insisting it is not a major problem because the good and important games will be preserved anyway by people while the chaff that no one even wants to play will not (he e.g. seemed to consider a large part of the 8bit NES game base as such chaff that doesn't need to be preserved). No problem.
While there may be some truth to that, I also think it is pretty shortsighted. Many games, as well as e.g. movies, may become cult classics long after they were originally available, and maybe even failed back then. It we go by the popularity, then I guess e.g. "Plan 9 from the outer space" movie should have never been preserved, yet nowadays it is considered and important piece of movie history in its own way.
And it may even go beyond cult classics. It may be e.g. just me getting an urge to see and experience a game like
"Ring II: Twilight of the Gods", just because I have read some interesting tidbits about its obscurity that I want the see myself, regardless that apparently that game was not that well received in 2003.
For this game in particular, even though it is only little over 10 years old, I don't find any used copies here, and it doesn't exist on p2p networks either as far as I can tell (I saw glimpses of one of its CD images on one less popular p2p network at some point, but even that disappeared). I can see a couple of used copies sold on American ebay, maybe I'd need to check if they are willing to ship overseas. I bet in 10 years I'd have even harder time trying to locate this game.
This is why I always say "hogwash" to those who imply that everything you'd ever want will certainly always be available on pirate sites and p2p networks, so nothing will be lost, don't worry be happy. Those still depend on people like you and me having any interest in keeping preserving and sharing it to the world. Am I sharing obscure stuff I have and someone in the world might want to have too? No, due to various reasons.
So who exactly will make the decision whether certain piece of art(?) is worth preserving or not, and do that in time while it is still preservable?
Trilarion: For example: Preserving Day of Tentacle means that you have to implement the ScummVM machine over and over again on every new hardware/software plattform.
Or alternatively, emulate a platform which can run some existing version of ScummVM. Or DOSBox, I am pretty sure Day of the Tentacle runs fine on it too, albeit I haven't tried it.