Well, primarily because Steam is NOT "Always on". In fact, after installing a game and starting it for the first time, you never need to be online with Steam again.Azriel Nightshade said:Why is always on-line for consols detrimental, but always online via Steam exempt from scrutiny?
The only things you need to be online for with Steam are:
1) Downloading and installing games/updates (obviously)
2) Using of Steamcloud (optional anyway) and Achievements (which are optional, too)
3) To play Multiplayer games using Steamworks (in which case you need to be online, anyway even if Steam wouldn't be part of the whole deal)