Blizzard very intentionally made it online only to combat piracy. Not only that but I read they have units/loot/and map layouts generated server side to make i

Blizzard very intentionally made it online only to combat piracy. Not only that but I read they have units/loot/and map layouts generated server side to make it much more difficult for the crackers to release something playable. The servers are doing a lot of work, so it's not surprising in the slightest that they are having lot's of launch day issues. It's a pretty sad case of putting business concerns over user experience. If it wasn't an anti-piracy thing they would have happily made a offline mode because it would drastically reduce the server load and all the support and development costs that massive multiplayer games have.