satoru: Its kinda hard to say GOG is using a 'blue ocean' strategy when GOG has basically done everything it can to copy steam at this point. They renamed themselves from "Good Old Games" for a reason. That was the abandonment of their Blue Ocean strategy.
I don't disagree about that stuff. Galaxy was an obvious response to those who want cloud saves, achievements, auto-updates, etc, "just like Steam". Personally though, I still view GOG's "USP" (Unique Selling Point) as DRM-Free rather than classic games. As someone mentioned above, if they had stuck to selling just 90's games, at some point most "old school" customers will end up owning all that they want. They also wouldn't be any further along in filling in the "gaps", ie, they probably still wouldn't have NOLF 1-2, Dune, Diablo, etc, even if old games was their sole focus for reasons beyond their control.
But looking through my collection, in addition to the "Golden Oldies", there's also a ton of games made in 2010 or newer (eg, Dex, Divinity Original Sin, Don't Starve, etc), that I only bought here because they were DRM-Free and had offline installers. If GOG had dropped DRM-Free and the choice was Steamworks / CEG DRM or "GOGWorks DRM", I probably wouldn't have bothered (for the same reason I don't even look at Denuvo games either). I'm fairly sure GOG know the value of DRM-Free to their brand plus the "running theme" of how people feel in the forums. So as Steam-like as Galaxy is in everything except DRM, I also can't see them dropping DRM-Free. It would be branding suicide (like Coca-Cola dropping the red/white marketing and replacing selling Cola with generic bottled water...)
Edit: The other issue is "unique old games" were already under attack from 2 fronts as soon as it become apparent they're still popular.
1. Other combined publisher / stores "locking in" their old content to their own stores (eg, Blizzard's Diablo, Microsoft's Age of Empires, Valve's Half-Life, etc) to which the only real alternative to buy elsewhere isn't other digital stores but old 2nd hand discs on Ebay.
2. Remasters of old games end up on Steam anyway. However, had those old games not been remastered, we may have seen many titles like Baldur's Gate, Day of The Tentacle, Full Throttle, Grim Fandango, etc, as possible GOG exclusives (same as, eg, Sam & Max Hit The Road still is). Instead those original titles end up actually being removed from GOG).