The comparisons to Steam are false, because it would never be like that on a closed platform. The absence of competition would make it wide open to being abused -ie. the exact opposite of how the PC market operates.
You can go buy a DRM free copy of The Witcher 2 Enhanced Edition right now for $6, bypassing Steam entirely and getting it direct from the creators. None of the restrictions Microsoft were proposing have been remotely necessary in order to make that happen. Steam's sales (and overall quality) exist because they have to compete in an open market where anything can happen, not despite it.