This is the Achilles' heel of the Diablo3 launch: people who have already tried out BattleNet to play Single-player games and are fed up with it.
What did we gain from having to log-in every bloody time we wanted to play a single-player game?
Achievements? Games had those in Single-player for years.
Global Ranking? Posting one's score online has been done for decades.
New maps? Nothing that could not be patched in.
There was absolutely no reason for BattleNet, nothing the gamer gained. Quite the opposite in fact.
All that remained was the extra hassle and the inability to use the game you paid for whichever way you decided and whenever you could not access the internet.
I have recently read Ready Player One, a book about a massive online RPG quest. The villain is a greedy gaming company, IOI, that wants to hijack what used to be free, start charging for everything and demand a cut from every little transaction. Care to guess who this reminds the reader of?
Fooled me once...