The more these beliefs...
beliefs, you say? I don't believe that anybody actually believes all that claptrap about Xenu.. L Ron Hubbard made it all up to bilk money out of desparate people, and plenty of other folk are happy to continue the premise and keep the money flowing.. but does anybody actually believe it? I doubt it..
I may be able to provide a few insights on this.
My parents were in Scientology in the 1970s and early 80s. My mom signed up because of her sister and brother, and my dad signed up to meet girls (he was successful, as my parents are still together, so I guess some good can come from the organization!).
There are a few things you have to realize about Scientology; some of it has already been said. First, the nutso stuff isn't presented early on. It only gets revealed at a certain point, after you have invested years and tens of thousands of dollars. During that time, you are constantly bombarded with Scientologist propaganda and vocabulary, which serves to drive you away from your non-Scientologist friends. When you do "go clear" and learn about Xenu and the other stuff, they have done their hardest to brainwash you into their way of thinking. These days, they even install Internet filters onto your computer to block anti-Scientology websites.
Leaving Scientology presents its own problems. When my parents left, they lost all their friends. Their Scientologist friends would no longer talk to them, and they had already alienated their non-Scientologist friends. People higher up in the organization face more obstacles, including personal and legal threats. (My parents were never high up--an ex-Scientologist told them what it was all about, and they left. The church later sued him for all he was worth, and he had to publicly apologize and retract his words.)
Some of my parents' Scientology friends eventually left the church as well, and they've stayed in touch. One couple in particular was high up in the organization (well past OT3x--I think 6 or maybe even 7). Even after all these years, they still have a hard time not believing in Scientology's teachings, even the Xenu stuff. To paraphrase, they say they have a hard time accepting that they spent so much of their lives believing in a lie. It's not a rational thing, but then, faith often asks people to be irrational. When you've spent so much time having one set of beliefs drilled into you, it's hard to just let it go.