RWarehall: The game has only 14 reviews on Steam despite being out for 3 months.
Checking Steamspy, yesterday it reached a maximum of 3 Concurrent Users.
No one is buying this game. No one is playing this game.
Most of the time, "Why isn't GoG interested in XXX" is for this reason.
Also good points.
From Robot Riot's FAQs:
Q: On which platforms will the game be released? A: For the start, the game will come out on
Xbox One and Steam (PC and Mac).
Other
console versions for Nintendo Switch and PS4 are already in the making and will be released early 2019. There are also
plans to release a mobile version for iOS and Android, but there are no release dates available yet.
To me, that doesn't look, like they ever intended to do a DRM free (=GOG) version.
And after the lackluster salesnumbers, they feel even less inclined to put in the extra work to strip whatever DRM they may have used, and integrate GOG-Galaxy instead.