rgnrk: Probably another misguided dev that goes Steam only to prevent piracy. Probably their kickstarter promises of the drm-free version forced them to release the first game on GOG. (Back in the day, it was imperative for kickstarters to offer a drm-free version. Good old times).
This is exactly the case. And KS backers who upped their pledges to the $50 level when Stoci offered episodes 2 and 3 at that level are pissed off that they can't get them DRM-free. Stoic said they never made any promises about that. I (and their disgruntled backers) feel that totaly disingenuous.
rgnrk: My guess is it'll get on GOG at a later time, though. After releasing the first one here it would be bad manners for those who purchased the game here.
It's pretty damned bad manners to pull a bait-and-switch like offering DRM-free for episode 1 and then saying "We'll give you episodes 2 and 3 if you pledge $50 or more" and then turning around after the fact and saying "Well, we never promised the next episodes would be DRM-free, so we'll give you a Steam key". Anyone in their right mind would know those people that pledged would expect to get the following episodes with the same parameters that applied to the first, unless specifically stated otherwise. You don't expect moving goalposts unless warned of that beforehand.
I expect nothing from Stoic at this point, although I'm hopeful the next installments will show up here. I'll buy them at that point - at a steep discount.