That said, I'm sure there exist people who don't experience that. But that doesn't imply that it does not happen.
You have no idea about the level of conflicting messages you receive in these places. The advice is so diluted that it can't be practically applied, it only describes very generally the way the mind functions when it is operating at an average baseline. It doesn't mean it creates mental stability. These places run on belief systems, not science.
I am absolutely certain this is one side of a coin. On the other hand, these are difficult, systemic issues for which places like this serve as a sinkhole for. The people who work there have to deal with this every day, and I'm sure many of them are trying their best and are not abusing the power and authority they have been given over the lives of other people. But that doesn't mean it can't be improved, and it doesn't mean it doesn't warrant a real, socially active and involved discussion.
A client is a more engaged partner in the activity of achieving and maintaining well-being; a patient is a more passive victim of their situation.