21 points
You are spot on, DRM is the problem at the core. That’s why I prefer DRM-free stores like GOG over Steam whenever possible.
Luckily many of the old games I own on CD are also available on GOG.
15 points
Steam doesn’t enforce DRM, your game can use Steamworks even without DRM.
The no-DRM policy sure is very good, but in the end any game on GoG is there by choice of the publisher, who could also choose not to use DRM on Steam.
11 points
Many games on Steam use Steamworks DRM despite being available DRM-free on other stores, one prominent example being Batman Arkham City.