WoW had these issues when it was released.
Hell some servers went down for over a week early on.
Well WoW was a online game. So unable to play an online game because of the server/internet issue is still understandable.
But the online aspect of Diablo 3 was forced onto many of us. Many of us are not happy to register online when we just want to play the single player part only. And because of this online decision, we cannot play the game because of many server issue, even 2 weeks after the release, and have to deal with the risk of getting our account hacked, not just battlenet account, but possibly email account because the email account is used as the id.
Diablo 3 is a total fvck up, there is just no excuse for Blizzard anymore.