Breja: it has become entirely pointless to question why a game isn't here, or whether it might one day come here. You might as well pull out a OUIJA board.
That is mostly true. However, there are exceptions to that during the times where the devs publicly announce that they submitted their game to GOG and then it was rejected by GOG "curation." With examples like that, we can infer the reason why it isn't here (i.e. CountryBall Heroes).
But you are correct that it's pointless asking on GOG forums why a game isn't here, other than in those situations like which I've just described.
GOG staff isn't going ever to answer that kind of question, and forum users aren't ever going to know the answer, unless the dev directly comments on the matter.