I can't believe people are complaining about this.
How is this any different to any Steam-based single player game?
Ignore the multiplayer component for now, seriously how is it different? You buy a game on Steam, you have to log into Steam every 2 weeks to verify your account and then continue playing in offline mode while with SC2 you have to do it every 30 days, yet SC2 is the one people bitch about?
Steam is an online download service. It is a function of the service at the same time as it is DRM. It is expected to require internet access to use a digital download service. To think otherwise would be folly, how would you download the games in the first place? Plus as a digital download service it would be far to easy to just install steam on your friends computers and download the games if they did not have some form of activation requirement. Although even with that I think you could get around it pretty easily..
Starcraft II is available as a hardcopy purchased from a brick and mortar store. You should be able to buy the game, go home and install it without an internet connection. If it was a purely multiplier game this would be moot. However the game has an awesome single player campaign that many bought the game for. The only time I ever played multiplayer Starcraft was at LAN's. I have never played Starcraft on battle.net. There are many people who don't play games online and buy games just to play on their own at home. As it how it has been traditionally with video gaming. Yes the box says it requires an internet connection but the general feel of the game is still that of a typical video game. When you think Starcraft it is a completely different feel then when you think World of Warcraft.
Now that I think about it this way though I think this may have something to do with the way they allow all players to download SC2 from blizz's servers at anytime. In that case they should limit that option to those who purchased the digital download and have separate DRM on the digital download and on the hard copies of the game like other companies have done. Or have the digital download require battle.net logon to authenticate and have the hard copy require cd-key and disc in drive.
EDIT:
Too add, Steam is also different in that it is very popular and has a lot of different companies backing it. So in the event of it's servers going out of commission there is a greater chance of someone taking over.
Also after thinking about this for a few days, and see the good gesture that was that patch, if Blizzard was to remove the 30 day reactivation I would buy the game. I would still not be happy about the online activation being there, but being that given their current model and that is never going to change I see no other solution. It would be way to easy to distribute the game with their current model without any form of online activation. And a one time activation is something that can worked around and at least is within the users control somewhat. For example I can install the game to a USB drive and activate it at a friends place or something or somewhere where their is internet connectivity and then go where I don't have internet and play worry free.
EDIT2:
You have to be logged into your battle.net account to download it... so my above point is moot! You have to have a cd-key tied to your account to download, that is enough authentication right there. And the hard copy version could use cd-key plus disc check.
Still, I would reluctantly accept a one time only activation. But keep pressuring them to remove it from Diablo III... though I would probably reluctantly accept it there as well.