Daedalic is actually complaining about being ignored by Steam. They say, that they will be go bankrupt if Steam continious to ignore their games.
So "Sativas Ketten" will be published by Koch Media, they had great success with "Dead Island" and so they have no problems to put their games on Steam. Daedalic hopes, that they may get a foot-in-the-door with the game.
Steam apparently ignored earlier Daedalic adventures on the grounds that the target audience for German-made adventures is too small. and that's probably true. Germany (or German-speaking Europe) is the last remaining bastion of the point-and-click adventure game. no other country or region still develops as many adventures and in no other country do they sell as well as in Germany.
Daedalic is desperate to get onto Steam because in this day and age, their survival depends on getting their games onto Steam.
that's just the way it is. there's a huge number of PC gamers now that are digital-only and won't buy disc-based editions anymore. and a large percentage of those is Steam-only as well because they don't want more than one digital platform, which is reasonable IMO.
i'm glad to see The Whispered World on GOG but i won't be buying it unless they add German language as well. as a native German speaker i play German games in their native language, just like i play American and British games in English. for the same reason i already bought Sacred on DotEmu instead of on GOG... and Steam offers most games in a multilingual edition, so i'd go for the Steam edition tbh.