Everyone loves the movies.
With a movie, theatre is brought into a new dimension that is cost effective. A movie, printed on celluloid, allows more people to watch a film than you can pack into a theatre. With a movie, you can watch the tales of Haggard's hero Allan Quartermain; or Indiana Jones (which has little resemblance to Allan Quartermain); Tarzan, or any number of subjects. Movies that include realistic items like Chicago, or Silence of the Lambs, or even When Harry Met Sally.
To me, the purpose of a movie is to either Entertain or to Educate. In the purpose of Entertaining, a movie is supposed to be used to bring you into a whole other world. For the purposes of Entertaining, a good movie speaks to the inner child and takes you a fun journey to discover a whole new world and to have adventures. Movies have been following this purpose as long as movies have been produced.
Since there were silent films and talkies, films had been talking to the inner child inside of us. The original Thief of Bagdad, Sir Arthur Conan Doyle's The Lost World (which is one of the best books and recent films I've seen), and screen adaptations of Sir Arthur Conan Doyle's Sherlock Holmes with Basil Rathbone under the hat all the way to Rupert Everet and Robert Downey Jr. spoke to our inner child. There was many women's films, many films for young boys (including the all time movie serials like Buck Rogers, Flash Gordon, and Radar Men from the Moon); and films for young girls. All of these had their purpose to entertain the human being and speak to his or her inner child.
The other purpose of films is to Educate. Films have been used to educate, through entertainment, about a wide variety of moral and social issues. Many of these moral films are given the rating of R by the MPAA. Films like the Godfather, Other People's Money, and The War of the Roses are social critiques and moral tales. Some films are taken from Shakespeare and are also social critiques, as Shakespeare wrote to critique his own society (Shakespeare, in Romeo and Juliet, criticized the duel).
Not only that, but history is full of unspeakable truths a moral filmmaker can explore. The lives of Nero, Commodus, Caracalla, and Julius Caesar all have done terrible things that parents would not show their children. But they all make good moral tales through their actions and what they were trying to achieve. Caracalla, for instance, was a cruel emperor who built a lavish Roman Bath complex in Rome.
To create a moral film and to water it down for families is the worst thing a moral filmmaker can do if he wants to impact his audience. He's crossing into the territory of the Entertaining filmmaker, who makes movies for the inner child. For while the moral filmmaker tells about reality and seeks to educate the populace about Social wrongs, an entertaining filmmaker must give up his quest for accolades of Oscar to tell stories that entertain and speaks to the child. In the case of the Entertaining Filmmaker, it's better to speak to the inner child and to make a PG-rated dream than a PG-13 misdream. An entertaining Filmmaker, after all, stands on the shoulders of those who wrote movies for children.
Adventure, fantasy, and comedy are the realms of the Entertaining filmmaker. You make a film to tell a story that speaks to the child. It requires deft storytelling and deals with the universal morals of right and wrong, love and hate, and all the tools of adventure fiction that writers had used ever since. Although there is room for social and moral commentary, the emphasis is on entertainment.
However, mix these two aims, and you get bad movies. Ferngully is a great example, and by all reports, James Cameron has learned his lesson and created a fantastic movie by the name of Avatar. Avatar has strong parallels with Ferngully, but James Cameron used the premise of Ferngully and improved it with the tools of Science Fiction (Avatar, by many reports, brings you into a whole other world, while Ferngully was a propaganda piece).
But it's better off if the Documentary Filmmaker can check and recheck his sources when he writes his documentary. Filmmakers who don't do this may find themselves in trouble.
However, whether the filmmaker is a documentary filmmaker, or an entertainment filmmaker, or a moral filmmaker they are all at once storytellers. They tell stories on film. They are also responsible in anything they do. A good film may entertain or inspire your watchers. A bad film tanks. A good film is enjoyed by all. Some people may recognize it for what it is (the recent Sinbad animated film has D&D written all over it), others will simply enjoy it. It's the duty of the filmmaker to bring truth to light: whether their film is excellent (Avatar, Star Trek), good (Night of the Museum), bad (Attack of the Killer Tomatoes, Ferngully), or utterly unspeakably terrible (Mars Needs Women). A good filmmaker always strives for excellence. A bad filmmaker is just wasting a hard drive and celluloid.