Actually, Crowley had so many children by different women and took care of none of them. I'm not sure how anyone would track all these kids. Many are dead, and many changed their names so as not to be tied to the name. He was apparently as drunk, abuser, womanizer, and full blown Satanist. No one would want that as a legacy (well maybe the Beetles and Jim Morris and other rock bands that were followers), but not too many children would want to be known as his offspring.