I've read reviews about the alcohol techniques and the dietary techniques as being nothing more than "just stop drinking" and "just become a vegetarian". But I've also read reviews of the very same books that the sound like the reader had the same experience I did with quitting smoking.
So maybe the bad reviews are just the people who the concepts didn't make sense to, and just like every other person who has ever come along to get them to stop this behavior, they shut down and clung to the addiction's false security, rather than be berated and belittled as a brainwashed zombie who has made an incredibly long chain of terrible mistakes to the point they have stockholm syndrome.
The good reviews are people the concepts did resonate with, as evidenced by their elation due to not paying for the opportunity to kill themselves any faster than absolutely necessary.