According to
this post by a blue, Dark Corners of the Earth was removed because of legal issues, not because of the bugs or the save file corruption issues, or whatnot.
This is all speculation on my part, mind you, but, like others, I, too, think we're witnessing a "Re-Volt situation", a game that was removed from GOG because the modding community asked for it, rather than the publisher. Zenimax/Bethesda own the rights to the game (they fully own the rights of the PC version), and we all know Bethesda is on GOG, so the chances of this being asked by Bethesda are next to none -- you can still buy Dark Corners of the Earth on Steam, which you wouldn't be able to do, if this was something at Bethesda's level. The thing is that the GOG version is different than the version Bethesda sells on Steam, and we have to look at those differences: mods, patches, fixes, all developed by individuals who are not related to Zenimax or Bethesda in any capacity. I'm assuming that as soon as some or at least one of these people got word that GOG was selling a version of the game with their patches and fixes, they asked for the game to be released, as Bethesda, the publisher GOG works with, doesn't have the right to sell or monetize their products, and now GOG is trying to solve this in a legal capacity, while trying to get the game back.
Some times using community fixes and patches included with the sold version of a game works wonders, and the modding community is nice and cool about it, like what happens with Vampire: The Masquerade - Bloodlines, the version of which GOG sells includes at least one major community patch that fixes a lot of stuff in the game. Other times, though, like what happened with Re-Volt, the modding community can be a real pain in the butt, and will complicate things as much as they can if they're not getting acknowledgement or revenue (Re-Volt got removed a few years back because some guy who modded it claimed to have rights over the game, and I assume GOG is still trying to get it back to this day, to no avail).
If this is, indeed, the case, then I hope GOG gets the game back soon enough, even if it means selling it completely unmodded and unfixed, the way Bethesda sells it on Steam. I've been playing Dark Corners of the Earth on PC practically since it came out, ranging through a lot of OSes and different hardware, and we *know* this game is problematic and has a lot of issues. It was nice of GOG to give us a semi-fixed version, but if the people who made the fixes are going to be whiny little douche bags about it, I'd rather have the game completely unmodded, but at least available to purchase, and get the mods later, on my own.
Luckily for me, I managed to get Dark Corners of the Earth, just like I managed to get Re-Volt, before it, so they'll stay in my library. But it's still very sad that a lot of GOG costumers will not be able to buy these games, particularly if the modding community (which gets so much praise in the PC world) is to blame.