I think the poor reviews are due to the perpetrator's family and children's parents being featured. But this tactic is not uncommon - that does not mean the documentary makers agree with their perspectives. If anything, including them highlights their hypocrisy and evil.
The accounts of the children - because they are children (the label 'teens' diminishes this) - sent to wilderness camps was genuinely devastating and moving. This camp might have reformed behavior for some kids, but torture is not an acceptable method of reforming behavior.
I feel almost no empathy for the parents. At minimum, they knew they were approving a staged kidnapping for their children. The kidnapping in itself can be traumatizing. Knowing that your parents signed off on your torture is even more traumatizing.
This documentary should have also included the names of all the children who have died in wilderness camps inspired by Steve's. This man's evil should not be minimized in any way. A lot of people need to be in jail right now.