Crosmando: Oh come on, multiplayer isn't just a missing feature, it's a very important part of a game which can change the entire experience.
I disagree for the most part. I have lots and lots of games where I am interested only in the single-player part and never even touched (or cared for) the multiplayer part.
I belong to the school of thought that in general, multiplayer and singleplayer games should be separate games. Very often either of them feels tacked-on, just because. The best online multiplayer games concentrate on being online multiplayer games, and don't even pretend there is some meaningful single-player campaign or anything there. Like Team Fortress 2 for example (and no the local training mode is not really single-player, it is merely for training).
Same for single-player games, the best single-player games concentrate on being single-player games.
Crosmando: You can't just cut out such an important thing and then sell such an obviously inferior version of the product.
So are you saying GOG should stop selling also all the old classics where only the single-player part is functional nowadays?
GOG can sell anything they want as long as they make clear what the game includes (or what it is missing).