vv221: I think they are both struggling with an understaffed Linux team (I would be surprised if there is more than 2~3 people in this team, maybe even a single one), and not willing to improve this situation.
I don't think they even have a Linux Team. They certainly state they don't give Linux support themselves, and that you need to get that from either the developer or the few Linux volunteers at GOG.
As far as Linux versions of games go, I've seen no real change in numbers here, and quite a few games I have purchased from GOG in recent times have a Linux version that I always download.
Even a number of recent demos here come with a Linux version. Why would they do that if they don't want to provide Linux versions still.
At the end of the day, it would be somewhat random, depending on the games you are interested in, whether there seems to be more or less of the Linux versions.
Couple that with the fact that GOG can sometimes be narrow focused on the games etc they get here.
That said, I don't chase after AAA games, so maybe there is less of those with Linux versions, which there could be a number of reasons for, especially as they are basically provided as a kind of bonus anyway ... and time and money seem to be everything to GOG right now ... they can't even provide decent server access to everyone ... in fact, that has gone downhill for myself and others ... so clearly they are engaging in cost cutting and penny pinching.
And you cannot ignore the fact that developer/publisher also plays a part, and always seem to be in a hurry to move onto their next money spinner. Adapting games for GOG costs time and money I guess, and Linux versions would be a secondary consideration.