A filmmaker's commitment to the artistic merits of a film can sometimes override his commitment to the truth of its message. Whereas, in making films, our commitment to our message might lead us merely to transliterate our arguments into video, rather than to translate them into an entirely different medium of communication.
At the extreme is [one director] who said: "All documentaries are propaganda … There is no such thing as objective truth, only point of view." Unfortunately, this is a common conviction among those on the far left. You tell your lies. I tell mine. May the better propagandist win. This is not a conviction we should entertain ever. We should tell the truth, insofar as we are able.
That doesn't mean we can't try to persuade and entertain. It doesn't mean we can't appeal to sentiments and emotion. It means that we must do so with good arguments and evidence, and without trying to manipulate the emotions of viewers. What we want to create are products with high artistic merit that also make our points. The best productions, I would argue, are those that best balance and integrate these competing tendencies, which best combine metaphor and message.
See the trailer for Acton's documentary The Call of the Entrepreneur here.