If you don't have rules that mediate joint creation, and yet you have rich fiction, then that fiction wasn't produced jointly, was it? It was produced by the GM.
I disagree. The decisions of the player's characters can dramatically change the direction of a campaign.
As @Campbell has just posted, this is a very common approach to RPGing. As best I can tell, from my own experience, plus reading about others' experiences, it is the predominant approach by a significant margin.
For some DMs yes. For public play and modules, of course. But there's nothing that limits D&D of any edition to strictly linear campaigns, and it doesn't have to involve narrative game elements.