It's entirely possible that sending the audience out feeling lousy was intentional

It is an exhilarating, distressing, funny and profound film, with one of the more memorable film scores in years,

Unshakable, witty and deeply felt, the film will be paying emotional dividends for a long, long time.

If you're interested in the topic at hand, you should just watch it and judge yourself because the reviews have gone very biased by people that didn't even watch it and just hate (or love) the creator. I liked it, it was well written, narrated, and directed and it was about a topic that interests me.