I can appreciate your ideal, Bill, but I think docs have gone too far down the road for them to be called "truthful". F is for Fake, Exit Through the Gift Shop, Michael Moore, Morgan Spurlock and even Errol Morris, let alone the one sided diatribes of conservative or liberal politics, or the religious wars come to documentaries. And what about 24 City? Is that really objective? I think we need to recognize that at least half of the documentaries out there aren't made with the ideal of objectivity, and the other half often fail at that goal.
However, that doesn't make them good films.