The similar parts are the ascension of the self as God, the role of will or intention in causing physical reality, philosophical dualism, reincarnation, etc. Once you've made it to the top of any of these pyramid groups, the "end cognition" is "lol scam!" So of course no one is going to embrace the "ideology" of some other group. Hubbard was obviously a brilliant magician. Just look at the effort required to undo his work.