It's true that the onslaught of remakes and remasters and rereleases serves a dual purpose - revenue and preservation - but it's pretty obvious that the motivation is entirely cynical. We wouldn't be getting all these remakes if they didn't sell or if fresh new stuff was selling better. And Hey! Look! Listen! Fresh new stuff is most certainly not selling because entertainers are clearly out of ideas and resting on laurels for so long has rendered them complacent. That, and they've worked really hard to destroy any competition that could produce fresh new ideas. (*glares at EA*)
If you look at many of the remakes and remasters and reboots out now - and not just for video games - it's pretty clear that it's anything that is even remotely likely to sell. And yeah, nostalgia is often the deciding factor in determining how much demand there is for this stuff, even if it can only sell to a niche audience. That's a pretty good indication that entertainers are creatively bankrupt.
That being said, it's high time preservation efforts get under way for video games. We're at a point when many games are at severe risk of being lost forever. Film preservation is serious business, but it's not a commercial one. Volunteers who actually care about preserving art are hard at work preserving and restoring film and they aren't in much of a position to make a profit off it. But the effort isn't nearly as extensive for video games. Few people even seem to be aware of the increasingly desperate need to preserve games.
That having been said, these remakes and rereleases still make games available that otherwise wouldn't be. Video games are in a unique position that old games don't easily transfer to new platforms. It's easy enough to print a movie on film as it is on compact disk or magnetic tape. It's a simple matter to convert a printed script into digital. But many games simply don't translate easily across hardware, which is their medium. But I have personally benefited from remakes and remasters of old games that I didn't have the chance to play when they first released. Since I never owned a Super Nintendo, I could only play Chrono Trigger for the first time when it released on the DS. I also got the chance to play Final Fantasy IX and Dark Cloud 2 for the first time on PS4 (even though I own a PS2, Dark Cloud was more readily available on 4). While I played the original release of Myst, I acknowledge that realMyst is an appropriate graphical upgrade of the original game that fully realizes the vision the creators of Myst had intended for it. I found Final Fantasy XII as it released originally insufferable to play even though I was really intrigued by a lot of things and really wanted to play it, and the tweaks the Zodiac version made finally made it enjoyable.
So yeah, there are uses for rereleasing games, even if the motivations are more on the cynical financial side. Nintendo markets its stuff almost entirely on nostalgia and name brands. I mean nostalgia is Nintendo's exclusive business, through and through. This is why they are so reticent to make new IPs. And I don't think this mentality comes out of respect for their IPs, since Nintendo is only ever willing to mutilate their franchises just so long as they can print a familiar name on the box. This is how Zelda gets turned into Wind Waker or Suckward or Zelda Creed: Far Cry of the Watch Dogs. And how Metroid gets turned into Federation Farce and Dumber M. Or Star Fox into The Legend of Krystal: Dinosaur Planet and Generic Multiplayer Arena Furry Shooter. Unfamiliar products with familiar names. If ninty was really in it out of respect for their entire library of games, the (S)NES Minis would have shipped with far more games than the select few they came with. As in, the system's entire libraries if nintendo really meant it.
And every second they spend rehashing the same old or just slapping a familiar name on a different package is time money and a complete lack of creativity spent not making new things.