> Valve could have made `steam.dll` optional for really old games but DRM is DRM and it's here to stay.

It mostly is if you digging a bit. Yes, it should work out of the box, but at least it's possible to make it work. When the battle of getting games to not permanently break is still being fought (not to mention that there's (somehow?!) significant sentiment that games permanently breaking isn't an actual problem), there's little wonder why the battle of inconvenient DRM isn't really happening.