Okay, here's my stupid take on it. I regard film as art, or an art form. And I simply see the film as that. In that sense it is extraordinary. If the cinematography alone doesn't winner an Oscar or Golden Globe then something is seriously wrong.
As for people being converted by the movie, it is a highly emotional piece of film and I'm not surprised that it would have that effect on people of weak character and or highly emotive personalities.
As for the violence, I can accept that, too. I believe art should reflect reality. Would Schindler's List have been as powerful without the violence? Would the Omaha Beach scene in Saving Private Ryan be the same without the violence? No. So for this art form, film, to be true to its subject sometimes it has to be brutal.
If you want a parallel in the realm of more traditional art I'd refer you to Picasso's Guernica -- it's a horrid landscape of pain and suffering because that's the only way the artist could convey the reality.
P.S. Maybe I should have prefaced this all by saying I believe that the freedom of speech and expression are absolute rights. If anyone is interested in reading an interesting take on the work of a censor, can I suggest you read Areopagitica by John Milton? Milton and I differ on some aspects of the need of a censor; it is worth reading.
I think this link has a free version you can read: http://www.bartleby.com/3/3/