I think that we must separate the man from his creation. If we begin to judge the great geniusus of our age, we will never read anything, or do anything. Like Lillie said so wonderfully, Aleister Crowley was a human being, as we all are and should be. Perhaps he made mistakes on the way, and perhaps he really was a bad man, but in the end this does not matter.
Hemingway was a drunk, Oscar Wilde was a closet homosexual who was put in jail for his practices, Poe was manic depressive... the list goes on and on and on... The problem with raising anyone on a pedestal is that we forget that they were human, and flawed, and then proceed to judge them far too harshly. While I would not read "Mein Kampf", Hitler did indeed do great things, and abominable things during the course of his life. But I digress. He was a truly evil man.