I don't think I share your opinion. Perhaps if you gave some examples I could understand your point of view. However, I just watched this, and what I took away from it was primarily a sense of despair regarding the welfare system as a whole. Watching this documentary was excruciating.
In terms of bias, I think the documentary captured it, but I didn't feel like the movie *itself* was unfairly biased. It appeared as though every character (except maybe a few at the very top) were on the receiving end of some kind of bias and/or unfair emotional abuse.
I came away from this feeling badly for humanity in general. Neither race, gender nor age seemed to exempt anyone from misery in this documentary. But, as hard as it was to watch, it felt like a validly encapsulated story about welfare.