That's a funny way to spell Diablo II

May depend on the genres one focuses on as well. But I'd agree with that, myself, though at the same time I must admit I couldn't really make a solid case for it. With my focus on RPGs, I guess in my mind the "classic" age ends with Bloodlines and KotOR2... Which is odd, considering how flawed they are, too ambitious for the resources available. But that may be just it, the moment when the technology evolved so much and the perceived requirements to make use of those innovations became so taxing that games based on really good and complex ideas could no longer be created and released. Or at least not by devs in that "sweet spot", sometimes called "AA".

I know where you can get old games (even part of the name of the place), if you don't mind the incredibly slow download speed....

The fantastic thing is that we can do more then one task at a time. Which is what GOG is doing, continue getting the older games that they can manage to, as well as selling a great catalogue of new games. Personally, I'm on here more for the DRM-Free aspect, so I appreciate GOG selling DRM-Free games in general.

In my experience most people regard Witcher 1 (2007) and TES 4: Oblivion (2006) as pretty old now.

The current "borderline" year of 2010 saw titles like Alan Wake, Bioshock 2, Darksiders, Fallout: New Vegas, Mass Effect 2, Metro 2033, Star Wars: The Force Unleashed II, Two Worlds II...

... interesting how some of them feel rather dated now, while others still feel very recent.

I just wanna play GOOD games.

This is indeed an interesting question considering how old e.g. The Witcher 1-2 games are now, yet many people who demand GOG to focus on "old games" don't necessarily mean "any game that is 10+ years old".

It appears to me to many of these people "old game" means "a game from the era before Steam existed, and which can't be bought from Steam". So, if it is a 11 year old game that was released on Steam already, nope, that is not an "old game" that GOG should sell. Anything that was released during the time Steam has been a thing, is "too new", from here to eternity.

So in essence what they are demanding is that GOG should sell only games that can't be bought from Steam. The age of the game is less relevant (but it makes sense that these games tend to be old "abandonware" games because ever since 10-15 years, almost everything has already been released on Steam).

If Steam is not selling e.g. Peter Jackson's King Kong game or Battle for the Middle-Earth 1-2, the reason most probably is not the games' age, but that they simply can't be sold anymore due to movie licenses etc. So demanding GOG to list them (because the games are not in Steam) is futile, as nice as it would be if those games were re-released digitally.

Was thinking after I posted that that Witcher 1 would be a counter-example to what I said, since I am starting to think of that as a classic by now. But then again, it was based on older tech, albeit heavily modified.
None of those you listed from 2010 strike me as classics. Neither does Oblivion, not in the least, in fact Oblivion is one I specifically think of as a notable representative of a shift to a new and much worse mindset in developing games.
Hmm, game released before Steam existed... That does seem like a decent separator. But it does move things about a year earlier, and isn't relevant in itself. (Not being sold on Steam is just silly as a condition though.)
Does tie in with something else though. The release of the Source engine, so HL2 but also, again, Bloodlines. Can take that as a moment that made tech maybe more important than the ideas and dedication of the devs, and when you connect it with the fact that it's Valve's tech and they ended up deciding the sale model for gaming too, seems even more fitting as a separator between classic and "modern".

Not if you take it as "sold digitally online". Retail games were dead when they ceased to be distributed in shops (sometimes little time after their release). Steam developed and normalized online editions, and those can keep ghosting forever on the internet. Games don't vanish fron online availability as easily as from shop's shelves.

GoG was precious, because it was fishing games out from the darkened area before this vaguely eternal online accessibility. So in terms of accessibility, this old/new distinction makes sense.

I do think a back-to-the-roots strategy would be a great thing for GOG! There are so many good old classic games in the world, which are still "offline" on GOG. Look at the Star Trek franchise: from 1990 to 2020 there were for sure 30 releases of Star Trek games on PC. Here on GOG i do find just 4 Star Trek Games...but what about Star Trek: A final Unity? What about Star Trek: Klingon Academy or Star Trek: Birth of Federation? Let us think about it together....

That all depends on the rights holders and what they want to do. Viacom/CBS and the various publishers (Interplay, etc) are the ones that have final say on which Star Trek games appear on GOG, if at all. There are rumours right now that Viacom/CBS (Owners of the Star Trek IP) are going through some hard times which may be causing them to focus there attention in other areas to build revenue (there are even rumours they are looking to sell the Star Trek IP which actually would explain why we haven't seen any new releases as if it did got sold GOG would have to re-negotiate contracts to release the games)

GOG is a company I've learnt to distrust on many levels, but not when it comes to their efforts for bringing old games to their catalogue. Even obscure or "niche™" ones. It's pretty safe to assume that if an old game isn't there yet, securing its rights must be near impossible. And its especially often the case with games tied to brands or franchises (like "star trek"). So I don't think that this specific issue here (the absence of those games or the minority of old games release) is much related to GOG going back or straying away from its roots.

Impossible? I do not believe in that. What about Blade Runner (?)...source code and rights to the game were very long time in "nirvana". And now you can buy the game @GOG for less than 10$. Where there is a will, there is a way!

Star Trek: Klingon Academy is from Interplay as Star Trek: Starfleet Academy does. So where is the exact issue with Klingon Academy after the release of Starfleet Academy here @GOG some years ago?

Just because they eventually succeed sometimes doesn't mean there aren't real issues with most of the missing classics. You don't think GOG would sell NOLF if they could? Come on.

I said "near" impossible. GOG probably didn't get Blade Runner by waking up that morning and deciding that this game would be an interesting addition to the catalogue after all. Getting the remaining games can be a very long, slow, complicated endeavour. See all the investigations on the rights for No One Lives Forever, for instance.

Such releases will be increasingly (wait, decreasingly?) few and far between. Will is not enough. And even when there is a will + time + work, it doesn't necessarily ensure a mean. Success in one case, especially when it's ben hard, doesn't mean success in other cases, and even less instantaneous success..