Easy. Crowley was a grifter taking advantage of credulous people for his own ends. "What has been will be again, what has been done will be done again; there is nothing new under the sun."
Grifter is uncharitable for someone that is dealing with esoteric things relating to the unconscious where words fail, and who openly admits that what he says isn't intended to be taken as literal truth- I mean he even titled his books things like "the book of lies." His intended audience is too intelligent to be easily "grifted" or to take him literally.
In the words of Garek (Deep Space Nine):
Doctor: What I want to know, out of all of the stories you've told me, which ones were true and which ones weren't?
Easy. Crowley was a grifter taking advantage of credulous people for his own ends. "What has been will be again, what has been done will be done again; there is nothing new under the sun."