I feel like you are completely missing the point of this game. LBP has a functional campaign, sure. The game is designed with a campaign in mind and level editing tools to aid it. Dreams is designed the other way around, as level editing tools (game engine) first and with a campaign second. It is why it is called Dreams, the entire purpose of the game is that ppl make, share and play together. There is no "fan-fiction" and "real" developer creations here. If anything, this viewpoint goes against what the devs want the game to be.
And for what it is worth, some of these "fan-fiction" creations look miles better than the actual campaign MM have made. Like, their campaign is easily some of the most uninteresting things created in Dreams so far.
Then I'll let you guys have it. I prefer single player campaigns with a beginning, middle, and end over "tools". The last time I was hyped for a game of this kind was Project Spark on Xbox One (not nearly as ambitious as Dreams, I know). I couldn't even force myself to play the prerequisite time that would allow me access to the Conker's Bad Fur Day "sequel".
Hope the audience it's shooting for has a blast, though. It really looks well made.
Yeah, I prefer SP games with start, middle, end too. That doesn't automatically disqualify Dreams. We don't know what ppl will make, but they could easily make smaller narrative games within the framework of the engine itself, that abides by a start, middle, end mentality.
But yeah, if you only qualify this based on what the dev itself makes then it is not what you are going to want it to be. There is a campaign, but it is short, so just wait for the game to be cheaper if you really want to try it out.