Emerikol
Legend
I guess the short answer is they wouldn't be fun and they wouldn't be awesome for me. Remember I said if it works for you then do it. Just not for me. I've played in games where the DM mostly made it up. I didn't last past the first session.Why? A group of friends get together and play a collaborative game. The Dm runs the world and the players live in it. At certain decision points the DM will make assumptions about my character background. At other decision points I will make assumptions about my character background. We are all friends; we all want to play in a good campaign; we all want to have fun; we are all working towards the same goal. So we work together and create pretty awesome campaigns, game worlds, role playing sessions and, well, we just kind of play Dungeons and Dragons.
Edit: I was probably too obtuse in my response. Even if you were a full-time Dm, paid by the hour, you could not fill out all the details of an entire world. Worlds are big and complex. Pleyers are a great resource. Also, the only thing that matters in the game world are the aspects that effect the players. Everything else is masturbation. Why not let the players become actively engaged in the world? Why not let them help?
Yes it would take a world to perfectly model a world. I'm not trying to perfectly model one. I do use abstraction. I detail out the nations and rulers. I detail out the regional cultures along with relevant racial outlooks. Then in the area where the players start I detail out the town/city and surrounding area. As the campaign progresses they are of course going to go to other areas. But with the abstract information I have I can extrapolate reasonable assumptions. I may not know the Sir John the Knight lived in Westover but I know that someone like Sir John the Knight does because I know Westover. So I put Sir John into the game as a new NPC when I need a knight from Westover. But after that Sir John exists and may even reappear. So as the group moves about I detail more of the world.
Gygax himself said that the campaign is more important than any player. I dont think he meant the group of people who played every thursday night when he said campaign. I believe he felt that players come and go. His campaign lived on with players coming and going for years. So his attitude was that the campaign was more important most definitely.
While I've had campaign worlds that featured more than one group, I personally like to do new worlds when I start a new campaign. I just enjoy the creative process. I might borrow bits and pieces from previous worlds if nobody ever used those parts.