Fair or not, reputation and corporate history allows different companies to get away with different things. Valve doesn't exactly have a reputation for turning off DRM servers, killing multiplayer servers for old games, and abandoning entire product lines and/or brands.

Conversely, nobody whines about Microsoft not releasing new versions of Halo, (or games in general with the number "3" in their title).

Steam is applauded for the incredible sales and cheap access to games. Also the convenience.

I have a steam library worth several grand, but I only paid a few hundred for it. Is anyone really convinced you will see Steam style sales on Xbox 1?

While I don't love that Steam has DRM, I don't hate their version of it either. What MS says they'll do (and what they'll probably end up doing) is nowhere close to what Valve has done. Valve has a history of listening to its customers about legitimate pain points with their DRM. Case in point: military personnel stationed abroad don't have the internet connection available to phone home every time they want to play a game, so Valve introduces an offline mode - authorize once before you deploy and freely play on that machine without an internet connection. Combine that with the fact that their DRM servers are pretty rock solid (I'm sure people have had problems with it but I've never encountered them in the years I've used steam) and the Gabe promise to unlock DRM if anything happens to Steam, and you get a lot of people comfortable trusting their game library to Steam.