Following some comments of readers on my The Sims Medieval review, saying that TMS had received "mixed reviews", I checked out Metacritic. Currently The Sims Medieval has a Metacritic score of 82, thus very similar to for example Rift at 83, and the same as Dragon Age II. Metacritic calls that "good" reviews, the "mixed" review category starts at 70 and below. But what was certainly "mixed" about the The Sims Medieval reviews was that when you cast your net wider, you will find everything from "worst game ever" to "absolutely fabulous". And, as already remarked earlier, it is usually The Sims fansites who give the less good reviews. People who come from role-playing or online role-playing games usually give The Sims Medieval better grades.
The German print magazine with PC reviews I'm subscribed to gives The Sims Medieval a mediocre 74 score, and complains about the quests restricting gameplay too much, and the mini-games for the crafting getting boring. At that point I realized that while the reviewer might have a point, the reason why MMORPG players tend to like The Sims Medieval is that in a MMORPG the quests are a lot *more* restrictive, and crafting without a mini-game is even more boring than with one.
So while browsing reviews I stumbled upon a review of a completely different game, the Gamespy review of Homefront. Quote: "Homefront is a modern (by which I mean "oppressively linear and highly scripted") FPS stripped of all pretense." So role-playing games aren't the only genre suffering from being oppressively linear and highly scripted. But for me this shows that the famous fourth pillar of storytelling risks overwhelming some games or even whole genres.
The problem is that the stories being told aren't mine any more. The more a game is linear and scripted, the less control I have over the story, and the more it feels like me passively watching a pre-packed story I couldn't care less about. I don't bloody care why exactly NPC Farmer Brown wants me to go into the forest and kill ten foozles, so even voice-acting won't make me any more interested in that story. What I want is my own story.
But that doesn't mean I want a completely empty slate. I certainly don't want something like Second Life. In games where the players are given all sorts of freedom to create whatever they want, the developers are forced to discuss concepts like Time To Penis (TTP) which describes how long it takes for the editor to be used to create something obscene. In MMORPGs where players are given freedom and PvP, they end up organizing ganking events.
Thus the art of a good game is to create an environment which offers sufficient freedom for players to create their own stories in, but with sufficient guidance to avoid them just wandering around completely lost, or so bored that they start annoying each other. Neither a pure themepark, nor a pure sandbox, but something in between. The Sims Medieval is certainly somewhere in between, which is why I like it, but unfortunately it isn't a MMORPG. WoW/AoC/Rift/LotRO are all too much on the themepark side for me. And A Tale in the Desert too far on the sandbox side. The previews of Guild Wars 2 are looking good, but I've long ago learned to not cheer for a MMORPG before I actually played it.
It all comes down to replayability and entertainment value. Highly scripted linear stories can be good, but at best only once. A game with total freedom and no goals at all gets boring fast, there is a reason why adults don't play in real sandboxes any more. But if a game can create an interesting environment where your decisions lead to the story being different every time you play through it, there is the potential for endless fun.