Simon Ludgate documents the experience of another big-ticket MMOG, Star Wars, the Old Republic. Like many others, this one is going from subscription to free-to-play. Ludgate characterizes this as failure. While it certainly is the failure of the revenue model, it may not mean failure of the IP. F2P products make plenty of money.
But before we conclude that to use subscriptions is to fail, consider venerable EVE. She has reached new population milestones in her old age, having never abandoned the old subscription model.
I think something cognitively different happens when we enter a world as opposed to a game. People will pay subscriptions for a world. They will not play subscriptions for a game. MMOGs interpreted WoW's success as a call to improve the game elements of virtual worlds. But they have overdone it. Today's MMOGs are all game, no world. Thus no one is willing to pay a subscription for them.
What makes a world different from a game? Well, in a world, there's downtime and exploration and life. Downtime is, moments when there's nothing to do. You just be. And it is nonetheless interesting. Exploration is, you go places simply to see things, to discover them. You don't get a reward, you just go look. It's a cave with artwork in the bottom, and nothing else. It's a desert to cross, in which there's an oasis with a palm and an interesting little bear who sings rhymes. And nothing else. Life is, when you go to a place and there are people just being there. They're not on a quest, they're not grinding a craft, they're not shopping. They are simply being.
Current MMOGs have lost elements like this, believing them to be boring. EVE has them in spades. So EVE can charge subscriptions - people like to quasi-live in EVE. Nobody wants to quasi-live in SWTOR, or, it is not possible to just live there. You can't live on a race track. Race tracks are for racing. You go around a few times and quit. Why subscribe to that?