I don't agree that it's brainwashing.
The way the system is set up, they are not deciding on what's right or wrong, they are solving an issue that's being problematic to individuals, that are by happen stance causing problem sin a whole. Brainwashing is the act of re-writing the brain to force it to act a specific way. What the PT do is just remove the limiter that's stopping it from working way it naturally wants to.
What they do is they go into an individuals psyche to see what's going on. In the game, it's in a thematic sense that they are stealing treasure, but what they are literally doing is going into a personality and finding out what the root cause of the corruption is.
They then proceed to remove the corruption, and then let the individual find it's own path. In these cases, it's the target's humility allowing their guilt to come forth, something their corrupt desire suppressed, denying their true personality from being able to work. It's a form of resolving a mental illness that the target never wanted, but needed help in removing.
They are not forcing their ideology on anyone, but instead removing a negative aspect that has corroded an individual's personality, and allowing all their other emotions to no longer be held back by the one desire that became too much.
In other people who don't have palaces, it's a case of them going into the collective metaverse and seeing if there's a shadow.
If there is no shadow, there is nothing to resolve, thus it's not actually a case of "a bunch of kids deciding on what's right or wrong", it's literally the case of a single person's negativity taking shape into that of a violent shadow that's is disrupting who they really are. It's no different then calling pest control to remove the termites eating your house.
(edited by Joker)