I generally dislike multiplayer in games and only really play single player games. I don't have much interest in multiplayer games at all really - I find other players ruin my experience and wreak the immersion. The only games I like to play multiplayer now are Minecraft and Terraria. I do occasionally play first person shooters multiplayer, but its fairly rare. In fact, the last few times it was two player split-screen modern warfare with someone who was sitting beside me.

So it should be obvious that I have nothing to gain from requiring a constant internet connection. I saw somewhere that Blizzard were saying they are requiring this so you can migrate characters between single and multiplayer without the risk of players cheating - this is just not a use case for me at all because I will never migrate my single player character to multiplayer. I'd much rather have an option to make a single player only character that doesn't require constant internet.

So besides not wanting or needing that feature, why else do I not want to be forced to be online all the time? I don't usually play games on a laptop while traveling, so that doesn't apply to me, but while I do have reasonably fast internet, over the past year I have had random disconnections (mostly due to issues with wifi, including wireless adapter breaking and wireless interference) and the occasional outage. Usually when my internet isn't working, since I use it for work, I will fire up a game for a little while until the internet is working again or until I feel like fixing it. I've already been bitten by steam a few times so I now default to leaving it in offline mode, only going online when I want to check for updates or buy/install a game. In the past three months, I've been irritated more than a handful times that I couldn't play certain games because I didn't have an internet connection for whatever reason. While this alone wouldn't put me off buying a game, coupled with my overall distaste for multiplayer, I don't see why I should have to pay (in frustration) for being online when I play a single player game.

So, for those reasons, I will never buy Diablo 3, even though I was looking forward to it.

It sucks because Diablo 1 and 2 supported local play but if Diablo 3 were the first in the series I don't think anyone would be complaining.

This is a step down in features for the consumer (just like the step down in features for Starcraft 2 from 1). There's no reason to paint a rosy picture about it. Last I checked there were still more active custom Warcraft 3 games than SC2 games and that speaks volumes.

You honestly think they said "hmm, let's save money by requiring online to play so we can better serve the customer." or do you think they said "let's make more money by further ensuring the integrity of our real money auction house and giving us more control over the product."

I have to disagree. Diablo 2's robust player economy was the driving force behind the game's lasting success (hence the advent of cash auctions in Diablo 3).

Hell, my favourite mod is still being actively developed: http://modsbylaz.hugelaser.com/