They are doing this for D3 because of the real money AH they are setting up. If you can go offline and just auto-kill bosses or spawn gear for yourself, then pop online and sell it for real money, it becomes somewhat of an issue.
At least that is why I think they are doing it.
Hardly, as the singleplayer and multiplayer parts of the game would be separated like they are in Diablo 2; you can't go online with your singleplayer characters either. Though what you can do is create a multiplayer-game for yourself with a password only you know, then just do exactly what you described.
Im highly curious. How Old are you? and where do you live?
Reason being: If you played Diablo 1 and 2.. surely you must be an adult by now. You can always move? If you're living in Moms basement and want to play your video games I have no sympathy for you.
Second question: Of course if you live in the arctic or some whack region that doesn't support cable internet for miles thats a different story. I am pretty glad Diablo 3 doesnt have offline play. with the amount of bugs and glitches and hacks in D2, anything Blizzard can do to minimize people who ruin games like this the better.
Moms basement? Arctic region?
Personally I live in greece. I guess it's the same with the whole Balkan region. We have frequent disconnects, lousy connections in general etc etc.
There are a few times where it FREAKING RAINS and the internet providers here crash. Note, I'm leaving in Athens not a remote village.
My solution so far have been to play single player games whenever my internet is acting up.
Not any more. Welcome to the future of single player games, where internet connection is required.
For laughs, the results of speed test on my old ISP (NOTE: i know that speedtests are not everything, i'm putting this just for laughs.)