Hi Jack Bauer,
Welcome to ESMB.
I was in scientology for 20 years, in New Zealand. I worked in the citizens commission on human rights (CCHR) which was closely associated with the office of special affairs (OSA).
You pose a question which has taken me a long time to answer for myself (I am now in my 10th year of being fully out of scientology).
I saw things, did things, which I probably will carry some shame on for the rest of my life. I'm learning to live with it, best I can. I've done some deep work to recover as my leaving caused real trauma. I was very unwell for a few years. I am well now, due to working with some highly skilled professionals (yes psychs!).
I was exposed to some "heavy" information via my work with CCHR and OSA. Why did I stay, why did I suck it up without questioning? Why was I like some robot that had lost touch with her own inner guidance/instincts?
To answer that would take a book because humans are complex and there is no easy black and white answer to fulfill the void so many have about true mind control. How do you control another human? How do you undermine their own core values, their own sense of themselves and replace that with something else which makes them pliable, usable, servile?
I can only answer that from my own experience(s). I am no expert in any of this. I can only share that which I experienced/learned along the way
out of the cult conditioning.
Scientology is an extreme form of mental manipulation. Right from the first day layers and layers of conditioning are wrapped around a person which alter their own view of themselves, and the world, and replaces it with an altered version useful to the cult (I call this the cult identity). It is a "brilliant system" if viewed from that perspective.
As the person goes deeper into the conditioning, gets more involved, many many aspects come into play. Everything from social connections, family, a strong sense of belonging (big subject belonging), and various other factors "glue" the person to the group. The training turns the person into their own "mental prison guard". Each time any doubts may enter thoughts, the person is trained to squash it, introvert and find fault with self. The group, the system, is always perfect, the individual questioning or doubting it, is the problem.
Add to this the heavy incessant carrot factor. Scientology is the "only way to eternal total freedom". That's a concept that anyone that has not been under the spell of struggles to comprehend. If the scientology conditioning is done "right" you "know" you can never leave because your whole eternity will be unspeakably ghastly. You are trained to believe that the entire planets survival depends on the success of scientology completely permeating society.
So, when you come across someone writing/saying stuff about how looney/bad scientology is you have massive conditioning filters that block out any level of acceptance of external information. The cognitive dissonance is extreme and the easiest thing to do is to fall back into the arms of the cult system.
It takes enormous courage to admit you have been seriously conned and to face your own inner vulnerabilities and step out of the whole fake mental manipulating system. The fact is many "ex's" don't fully drop the conditioning. They still cling to some of the tech because it is way more comfortable that way. Please note I try to not judge these folk because I could have easily been one of them. It was very painful to give it all up and regain my own sense of myself, think my own thoughts without them being tainted by the heavy conditioning of all those years in scientology.
I hope this helps you understand, if only a little.
Enjoy your time on ESMB. It's a robust cyber community, with a wide range of views.