The way you view DRM is how I view nonfree software. GOG and Steam both distribute nonfree software therefore I simply choose the one that supports my platform and is easier to use for various reasons.
While both GOG and Steam distribute nonfree software (for the others reading this, rusty refers to
Free Software as defined by the Free Software Foundation where "Free" is about freedom, not price), DRM adds additional restrictions on top to not having the source code available. Free software at its core is all about giving as much control as possible to the end user, both from a practical (having the source code) and legal perspective (via free software licenses) (there is more to that, e.g. via copyleft -this is a pun on copyright, not about the political left- but the essence is that). So DRM-free games have less restrictions here.
Want to preserve software? Fine, get the developers to release it as free software. Doom, one of the most successful games series ever made, did it -- the worst they can say is that it contributed to the series' overall popularity thanks to helping the "modding"/fan community. Arx Fatalis has a well maintained community edition thanks to its source being released as free software. Siege of Avalon received an updated re-release on modern platforms/storefronts earlier this year thanks to fan work due to it being released as free software. So on and so forth.
I fully agree with that, in general there isn't much of a practical issue for games to
not have source code, aside from middleware licensing. Unlike productivity, office and other types of "non-entertainment" software, games are generally "done" after release - patches, etc aside. Games that rely on online features, like MMOs, are an exception but even those are largely about the infrastructure than about the client software itself. A common given reason is to avoid cheating, but that is essentially security through obscurity instead of properly secure code - and even in that case, one could simply use slightly different executables for the "official" vs "source code" versions. The official wont be exactly Free Software but people who care about it can still use the alternative version (this is what the Cube engine games did actually and those were developed as FLOSS from the beginning).
On the topic of GOG -- what has GOG preserved that wasn't already preserved in the same state? Basically every old game they're selling was already floating around as abandonware. They simply wrapped it up in a zip file with dosbox and/or the latest fan patches.
They make the games playable out of the box - or at least they used to at the past. Also they ensure you get a proper copy - abandonware sites often use files that were floating around since the 90s (especially for older games) and those files are sometimes modified or have parts removed to delete
I know for a fact that they have made many games much harder to find despite not even selling it themselves(e.g., Buck Rogers Gold Box games have been removed from popular abandonware sites.)
Eh now, it is incredibly trivial to find those games. Buck rogers even appears on the first page of Google results (yes i tested the download).
And thanks to GOG shipping games with fan patches, it's sometimes difficult to find unpatched versions of certain games at all.
Yes this is sadly true, especially if you want to try and play the game on period accurate hardware. Advent Rising is such an example where they have the fan patch preinstalled - though since you do the download manually and aren't forced to update it, i simply kept my older version without the fan patch. Tough luck for people who buy the game nowadays though. You
might get an older version of a game if you contact support (i've seen some people saying that in the GOG forums at the past) but never tried it myself.
Valve employs quite a few developers who work on free software projects such as the linux kernel, wine, graphics drivers, and so forth.
And that is great, which is why my plan for my next PC is to install Linux and use DRM-free games from GOG, Zoom, etc via wine/proton on an AMD GPU (which has open source drivers).