The concept of the 12th house being the house of self-undoing, secret enemies, illness, and imprisonment has been around for a couple of thousand years. It certainly pre-dates Aleister Crowley.
The 12th house is cadent and in aversion to the ascendant. Basically, it's a blind spot for the native, a place you can neither see nor control, and one of the worst in the chart, and astrology has pretty much borne that out, unless you believe that all astrologers always have been 'corrupt holy men'.
I don't believe that. Astrology was the science of the day for 1500 years or so because it explained how the world works and it did a pretty good job of that explanation. Information was handed down and passed around - of course. Thoughtlessly - not so much. The idea that the only information that survived is from bad people is highly speculative. Do you have any training in ancient languages and training in how to read ancient and medieval texts? Have you read any of these guys?
I have, and I can't buy your theory. But I do accept that people can model astrology in different ways, and if it makes you happy to believe that no bad is reflected in the chart, more power to you. But you needn't try to discredit all the astrologers of the past to do that.
ETA: I missed it at first, but I realise you said that an astrological chart only shows one's consciousness. This is a new belief, and far from a universal one. My statements are predicated on the belief that life does go on outside of one's self, and that there is much that happens to us that is beyond our control. In any event, I meant no offence, but whatever you believe, you really don't need to trash the astrologers of the past to believe it. Crowley wasn't a bad astrologer, either. I grant he held some pretty odd beliefs about religion, but I've read far worse than him on the subject of astrology!