Speaking to Develop, Gibeau said “I volunteer you to speak to EA’s studio heads, they’ll tell you the same thing,” he said. “They’re very comfortable moving the discussion towards how we make connected gameplay – be it co-operative or multiplayer or online services – as opposed to fire-and-forget, packaged goods only, single-player, 25-hours-and you’re out. I think that model is finished,” adding that “online is where the innovation, and the action, is at.”
Here's the one glaring problem with this idea: Sometimes people want to play alone. They don't want to solo in a MMO or do a co-op of a map that they could do on their own; they want to be alone. No one else. No chat or voice, not even another name running past on their screen. Sometimes people want their own world. Their world and only their world.
This isn't merely a social vs. non-social mood issue, though that is part of it. It's also that there are things we can do in single player that we can't in multi-player. Like cheat as much as we want. Sometimes people want to type poweroverwhelming and just wreck everything. Or they want to mod their game, tweak difficulties, add content.
Then there's the aspect of gameplay: single-player games can offer better gameplay. Ignore the AI for that claim, my focus is on the choices a player can have. With no lag, fights can be faster-paced. Abilities can be more complex. Difficulty can be variable, beyond the harder-but-different methods we saw in Ulduar and ICC.
If Mr. Ebert will allow me to briefly suggest that games might be art, or at least to use art as an analogy, there are paintings and sculptures and different paint choices and techniques and a million ways to make art with are entirely not alike. Maybe we can do more with paint than a block of rock, but only an idiot or troll would claim that "sculpture is dead".
In closing, I'd like to suggest that in the third galactic rotation of the eighth universe close when we are all part of the robotic hivemind, that yes, at that point there may be little sense in developing single-player games.