In a couple years, the only new games available will likely come from online distributors with DRM abilities.
And that'll svck.

(Yeah, I bought like 8 games during the Steam winter sale. Doesn't mean I think that "forced online" should really be the way for the industry to go. And certainly not in the short term, while many people don't have cheap/reliable/etc broadband access.)
One obvious example would be when Steam forced us* all to upgrade to Skyrim 1.1 & 1.2, even though they screwed up stuff. The difficulties rolling back to 1.0 so that we could play the game again are also on the list.
(* yeah, we'd checked "don't automatically update". It ignored that, and did it anyway. And "just stay offline" doesn't work.... because, you're right - Steam has some good features. Like sales. And updating other games, that actually got improvements from their patches. So switching to offline to keep one game from shooting itself in the foot means you're suddenly locked out from all the other features.

)