AB2012: I think the main point actually flew over your head, and you seem to have it back to front again.
And as I answered you, in the grand scheme of things it doesn't matter at all; You have a lot more peoples who cares about multiplayer, achievements, cloud save, auto-updates, etc... than you have peoples who wants to runs games on their long dead original OSes.
And Gog and most other stores have always been about having games run on the latest OS (or at least the one with the biggest market share). So when the choice is between adding new feature that a majority wants, while still keeping the game DRM-free, or not doing it because a couple of peoples might want to have said games continue running on their original OSes, then it's perfectly logical that Gog chose the former and it is silly to expect them to do otherwise.
Backward compatibility with older/original OS has never been an objective for Gog or most other online store for that matter, only compatibility with newer OSes, also , a majority of peoples wants achivements, cloud save,
AB2012: the only real takeaway from your posts is that if you want the maximum possible forwards & backwards compatible version, "don't buy the GOG version
The takeaway is if you want maximum possible forwards
and backwards compatibility don't buy from a shop that, since the beginning, is all about forward compatibility and never cared at all about keeping backward compatibility.
I do think that it would be important to have some "libraries" that keep a a bit for bit original copies of games for historical and preservation purpose, would it be great if Gog provided this "feature" (as in possibility to download the unaltered original binaries of the game), yes of course, but it never was something they ever promised or said they would do.