The games people are playing right now will become nostalgia fuel in 10, 15, or 20 years, once such a point comes where Steam or GOG no longer exist, or the technology changes making today's games unplayable. The market won't die; it will just shift, fueled by nostalgia for something else.

Crappy games are crappy games regardless of time. I will have no nostalgia for CoD, Assassin Creed, Final Fantasy XIII or DLCs, QTEs and IAPs

In the same way that I have no nostalgia for 90s, 2000s and 2010s music.

It's 2016. How can you have nostalgia for music still being made? :P

I wish it was because it really sucks SNES games weight hundreds of pounds. Kids getting crushed under the SNES cartridges etc., not a nice sight.

Is this a bad time to admit I plan on getting the new NES CLASSIC MINI when it hits shelves November 11th? :D

This exactly. People look back to what they played or saw when they e.g. were kids or young, it brings back memories etc. For instance those two kids who play Minecraft so much now, I am quite sure at some point they get nostalgic over it when they are 30 or 50 years old.

Also, people are (later) maybe less nostalgic of something they experienced in their 30s or 40s or whatever. Young people and esp. children tend to get more emotionally attached to something they experience. Like so many great(?) movies from when I was young, I don't think it is because they were really better movies than what is being made now, but I just wasn't as jaded about movies as I am today. Today most things are much more meh than when I was young, or at least I tend to demand more from my entertainment.

They will stop being nostalgic for boxes is what I mean, because they will stop associating childhood with boxes. Physical (scarce) alternatives or complementaries to nonscarce digital ones will always be in demand as luxury/status products, however. Like, these days, people born in the CD era are buying music on vinyl, mostly music by performers who'd died before the buyers were born. It's not because they're nostalgic for either, it's because they're signalling their status as rich assholes and/or music connoisseurs. Hell, I used to buy game boxes and action figures hoping I'd invite girls over and they'd be impressed. (Then I became homeless and signed up on GOG.)

i highly recommend to be on gog at least a year, collect some experience with the shitty steam clone gog turned into and then look if the statement you made is still true. it may was but that time is gone. yes, gog is doing it already!