Why are documentaries that deal with economic issues so lousy?

Documentary films that tackle economic issues are ovewhelmingly oversimplified, one-sided polemics, usually (but not always) from a far-left kind of perspective. Rarely is any attempt made to present the issues in anything resembling an objective way, or to let the audences make up their own minds about things. The filmmakers have a clear message that they are advocating- usually something along the lines of, "______ is really, really bad!"- and the film is an attempt to hammer home that message. Examples include Roger & Me, Life and Debt and The Corporation . That's not to say that these films don't have any merit at all- I actually like Roger & Me quite a bit, and Life and Debt is certainly worth watching- but there's no denying that the perspectives are one-sided and polemical.


Why is this? You might argue that these films have to be that way because audiences are stupid and they don't like things to be complicated. But that doesn't really explain it, because there's another more popular genre of documentaries where the norm is exactly the opposite. I'm thinking of character studies, like Tyson, Crumb, or Grizzly Man. The intention is these films is quite clearly to unpack the complexity of their subjects in a way that often seems to conciously promote ambiguity- a film like Errol Morris' The Fog of War, for example, wants you to see the different sides of Robert McNamara, appreciate the context and significance of his actions, etc. It's not trying to convince you that McNamara is "good" or "bad," in fact sometimes it feels like it's trying to prevent you from drawing too strong of a conclusion one way or the other.

All else being equal, you'd think the audience for documentaries about economic issues would be at least as smart as the audience for character study type documentaries- so why are the ones about economic issues so much more simplistic?

My only theory is that there may be some sort of path dependence. There are only a limited number of movies that are going to get made, so the outcome is not going to look like a competitive market. It may be that audiences have just come to expect movies that deal with these kinds of issues are going to be lefty polemics, and a film that took a different approach would have to struggle to overcome this perception.