Is it feasible to just abandon keys altogether and sell only directly through a given platform (Steam, An appstore of some sort, etc)?
This means Steam doesn't take a cut of the sale price. But the developers still get the benefits of Steam community, Steamworks drm, and potentially having a unified update/distribution channel.
Similarly, some gamers prefer to have games 'on Steam' rather than DRM free so that they have a single unified game library.