I'm not sure how you could have a unifying vision for something as broad and diverse as "the future," or "the good parts of the future," without projecting it down into a simplistic, synthesized work of very fictional storytelling where all resemblance to reality (and consequently all authority) has been sacrificed in favor of comprehensibility and persuasiveness.

In other words, the clearest route to getting people excited about a World Fair involves sacrificing the reason you'd want people excited about a World Fair.