User blog comment:Ausir/Diablo III requires constant Internet connection/@comment-173.45.200.131-20120510053441/@comment-2154860-20120510084752

Money, pure and simple. They take a look at how Diablo II is judged as a good game due to its playability on Battle.net and figure it's valid that everyone should play it online in spite of it being essentially a single player game. On the other hand, Starcraft II was handled the same way, and I expect that within a year, you can download a patch that will allow you to play it offline. It won't be by Blizzard, but someone will definitely crack it.

Ubisoft went the same way, and they're putting an end to this sort of DRM because it's hurting sales.