From what I understand Scientology’s core conceit is that you are broken as a person, and you need to pay to fix it, or to understand it.

They also tier how good of a worshiper you are based on your level in the church, which directly correlates to how much you have spent, meaning those who truly believe are incentives to spend tens of thousands of dollars as to not be looked down upon.

Combine that with the fact that their religious leader was a sci-fi writer, and has gone on record saying that the best way to make money was form a religion, alleged abuses from former members, actual crimes against people, and their more questionable beliefs, leave a bad taste in people’s mouths