Klumpen0815: It's all simply because someone high up with no contact to customers whatsoever decided, that Galaxy is the future and that directly competing with Steam instead of trying to stay in a small but secure niche is a good idea.
Small but secure niche ? what secure niche ?
I have the feeling that a lot of peoples don't really know what that mean, for something to be a "secure" niche you don't just need to chose some "nichy" thing and roll with it; for example if you decide to only sell games with title starting with the letter "Z", it will definitely be a "niche" but definitely not a "secure" one.
For a niche to be viable you need to do something that nobody else (or very few) does and to have a big enough market for it, Gog niche used to be : selling old games DRM-free, they didn't really "create" anything niche they were only selling somebody else old property.
The problem is that it wasn't a niche, more a bubble, It worked and was viable for a time because at the time were Gog started nobody cared about old games neither Steam nor even the publishers/right owner, so having a shop asking to buy old license for game that were no longer sold was interesting for publishers as they had nothing to lose.
But by being successful Gog effectively killed their own niche because they showed right owners that there was actually a market for old games and that basically if they wanted to make more money with their old games they could simply...well... sell them on Steam.
That's why we saw more and more old games, often games that were Gog exclusive, being sold on Steam, sometime even being sold on Steam months/years before being released on Gog.
That's also most likely why companies like Devolver manage to get rights for older games rather than Gog, because for a right owner selling a game to Devolver mean having the game on both Steam and Gog while selling it to Gog means having to... well... only Gog which is only a tiny fraction of Steam market share.
Personally, even though it's a pure speculation on my part, I guess that the reason why Gog decide to concentrate on more recent games, even if it means dropping some of their "values" in the process, is not because of some evil money hungry conspiracy but simply because they understood that their "old games niche" was dying and decided to concentrate on "DRM-free" games instead, regardless of their age.
But of course with recent games came all the issues of region restriction, local prices, patches, DLCs, etc...
Klumpen0815: By now most people think it doesn't need to apply to multi-player at all so this tactic does indeed work as always.
Except it was always the case on Gog, I don't know if you have very selective memory or you just weren't there at the beginning but it was always made perfectly clear, since the very beginning, that the DRM-free guarantee only applied to the single player part of games and not the multi player. It has nothing to do with Galaxy and it's not some recent decision of some evil ceo.