I must confess, I am a bit divided on this issue.
On the one hand, I'm not personally sure I would buy such games. I already have so many games to play on GOG as it is, that older games would likely always take the next place and be postponed forever.
But on the other hand, there are so many genuine classics that have appeared on consoles over the decades... games that are almost universally praised and fondly remembered, and can be said to have truly stood the test of time; games that have shaped the subsequent history of gaming, or that simply were, and are, fun to play. I'd like to experience them, finally (the only console I've ever owned being the old Atari 2600/VGS), and having them on GOG would be very nice in that regard.
Then, there are Commodore 64 and Amiga games. Some of them I'd like to revisit, to settle some old scores, if nothing else... others I'd like to try for the first time.
And we didn't even touch on the matter of arcade games...
Be that as it may, I agree with some of the above users that:
1) they should preferably come in large collections, dirt cheap, at least the 8-bit and 16-bit titles. For newer games, they could be sold separately or in smaller bundles (a single series, for example), but they should be quite cheap as well.
2) I'd like to buy just the ROMs and use them on emulators (but this could go against GOG philosophy of providing fully working games "out of the box", with no additional software or tweaking required).
3) the hurdles are mainly legal/financial, not technical.
4) it's not happening anytime soon.

Considering both the media that held these titles and the systems used to play them are slowly dying, and even nowadays I'm finding more interesting older titles, I'd be totally down to have a practical way of being able to buy, preserve and replay those games.

Oh, in a heartbeat. I'd gladly pay money to do things legally that I currently do illegally because there's literally no way to do it legally. (To me, an "out of print" product that's not available for mass market purchase should very quickly exhaust its copyright and become public domain.)

As much as I would enjoy playing console exclusive FPS games I wouldn't want to use a controller, so they'd have to actually be ported to PC for me to be interested. I'm hoping outfits like Nightdive look into this one day, porting stuff like Black to PC and modern consoles.

The other main genre I play is Western RPGs and there's not a ton of console exclusives for those. I use a controller when I have to for games like Dark Souls, so I guess I could be interested in emulated versions if the game looks interesting.

GOG is already selling console games, like Pulstar, and yes, I have bought those, so there's no issues either way.

If GOG had stayed true to its "good old games" fame, they could have had more emphasis on emulated games and all that.

The solution is actually quite simply too, make emulator software like C64 Forever the main product, and then have game files as DLC of that main product. That way there will never be an issue about somebody without an emulator accidentally buying an unplayable game image. With all that Galaxy nonsense that should even happen automatically.

If GOG won't do all that, I hope that someone else will. There are just too many good old games, in the real sense of that term, out there to be played that should remain playable too.

There are some old PS and Xbox-exclusive racing games I'd like to get a GOG treatment, like Formula One and Gotham Racing, but that will never happen because of the licensing issues.

In general though, I would be more excited to get an old PC game than console ports, since the genres I enjoy the most are more or less only found on PC.

At this point i don't see why.

You got Final Fantasy 13, 14, 15, Neptunia series, Deus Ex games, a hundred other 3D games, MMO's, Elder Scrolls, among many other games that have a high play count.

Unless you really like nostalgia, i don't see you playing any of the games even if you had them all.

So let's compare. Let's say i have Super Mario Brothers 1, 2 & 3. Perfectly usable games... I also got Skyrim.... Which of the four do you think i'll sink most of my time into?

Publishers should lose their ownership of the games (from the devs) after 10 years, and 10 years after it should be free to the world. Nintendo no matter how much they push it, their SMB game from nintendo isn't going to be a huge money maker for them 110 years after they publish it. Within 4 years books & games are no longer being produced, so the games in circulation are pretty much all the physical ones you got. Digital? You can copy infinitely, but i don't care how many copies of SMB i could have i only need one and even then i'm more likely to play something else.

Just my two bits on the matter.