The title and thesis here is a bit wacky. JPL itself doesn't have "occult roots." Parsons was into occultism and Thelema/Crowley, which is far less sensational than it sounds if you've ever actually read any of that stuff. It's not any more shocking than someone being into Daoism, esoteric Hinduism, Sufism, or any other minority (in this country) religious or philosophical sect. The beliefs involved are no more or less bizarre than the beliefs championed by much more popular religions.
I have noticed a tendency for creative outside thinkers like Parsons to be into "weird" belief systems. I've met a good number of really bright hacker types who are into all kinds of non-mainstream beliefs including conspiracy theories, Neo-Paganism, esoteric types of religion, strong interests in topics like UFOs and the paranormal, etc.