Many of the critics either didn't watch the whole movie or were so personally offended by what it demonstrates that they can't be objective. Nobody seems to challenge that this was a great documentary - informative, engaging, and new. The only reason they have left to hate it is to say it was unethical to make it to begin with.
To that, I ask whether they finished the movie or not? In the last scene, virtually all of the movie's "victims" were delighted by the big reveal that he was a fake all along. Many of them already seemed to know that and they just didn't care. Which shouldn't be a surprise, since he told them he was a fake throughout it, too.
Absolutely the best parts though are when he's meeting with other cult gurus and exposing their nonsense to what they assume is a safe audience who will believe anything.