I don’t know much about the cults surrounding Crowley. I just got the book.
But the same seems to be the case for most people who expound a liberating ideology.
If you read the bible the new testament basically does away with priests and temples; yet what are all these churches that I see?
In buddhism the Buddha gave directions to attain enlightenment or the cessation of suffering and it was open to all; yet so many cults and offshoots sprung from it.
It seems humanity has an inbuilt desire towards conformity. People want to be told what they want; it’s too much effort to discover it for yourself.
I mean I spend most of my time reading fiction and playing computer games. So I’m on no pedestal here.
To go to back to Crowley.
With Crowley’s magick being one in which people supposedly (I say that not because I don’t believe; but because i haven’t had it shown to me) collect together their intentional energy you can see how tempting it would be for a charismatic individual to manipulate a group into acting and intending his will instead of their own.
In fact the whole idea of a group is loss of self. One becomes part of the They the second one enters a group. Just depends on the intentions of whoever/whatever is guiding the group. Malevolent, benevolent, or just natural undirected something.
I’ve always preferred the latter two.
Subjective insights 
I’ve been reading Judith Butler lately, and following her I think that in a very real way, individuality may be almost an unattainable dream. Psychologically, the process of individuation implies an other; I am only me in relation to that which is not-me. Socially, from the youngest age and yes even every moment in our adult lives, we are beset by an other, in the forms of countless norms that shape who we are and what we do, norms that we neither create nor choose, but must adhere to in order to even be considered by others– norms that have come into being by the collective action of others who preceded us. I think that everything about being an individual human contains within its core this otherness, that I like to call immanent alterity, that actually forms us as individuals. Consciousness is such that we view ourselves as individuals, but it may be that it is this shared, collective otherness that is always at work in us that even gives rise to the possibility of any perceived individuality to begin with. And so maybe the conformity so many people exhibit is a natural response to the otherness that has preceded our individuation and caused us to even come into being as I’s among Not-I’s.
I think it may go back even further than that. When we first pop out we may be utterly undifferentiated from the world. From that state we then differentiate between everything else and care-giver and on it goes from there.
Or it may even be that we don’t differentiate between an I and an external world until we create the concept of 3-dimensional space – or that could be hard-wired. I talked about this in this blog: https://christopherjack101.wordpress.com/2014/07/31/babies-are-awesome/
The whole process of maturation could be one of an continuous or finite process of differentiation… That would be the buddhist perspective I suppose – – – you differentiate between what is you and what is not you till there is no you haha