Thing is, if you look at the ratio of violent/peaceful games, it's going to be heavily weighted to the violent side. GOG just shows this on a smaller level.
Of course. But just because everybody else does it, doesn't mean you have to do it, too!
Honestly, there are few if any games that couldn't somehow be called "violent."
BEFORE Doom, there were lots of other games without shooting or killing (living beings). I grew up with C64/Amiga/Atari and there were lots of games that were much less violent or harmless at all. There were times with hundreds of adventures (text, point & click and latter with moveable figures). There were many platform games, puzzle games, pinball games or abstract action games (e.g. Quix). There are such games on GOG but just a handful.
When I found GOG, I bought several games (most of them no shooting or killing) because most of them run well on our computer and they were quite cheap.
I just opened this thread as I hoped that others would also like to see less shooters. But I guess the GOG team isn't reading and thinking about this. Or they don't have much control about what games of their publishers can be released on GOG.
Converning Windows games, GOG.com is the only source for us as we run them on Linux and other publishing sites offer only DRM crippled software or games tied to any stupid download/online mechanism. That's what I like about GOG: offline, just install, no DRM. So, I hope that one of the next releases is not again a war/killing game.