You misread the quote, as well as removed it from context. Compassion implies superiority, but if every man and woman is a star, all are superior, all have inherent deity. None deserve compassion, but reverence for who and what they are, each going on their respective orbits. The wretched and the weak are most likely those who do not follow their True Will, and are slaves to causality. To stamp them out is not to kill them, as that would curtail their execution of their Will, but to empower them to aknowledge their inherent deity, thus "stamping out" the wretched person inside them in favor of the strong.
Do not try to connect the Book of Law with worldly views, it doesn't quite work. Christianity preaches compassion, yet was the cause of things like the Inquisition. Any scripture can be interpreted in any way, and not all that the BoL espouses has direct correlation with Crowley's own views. I doubt he was an objectivist libertarian, but even if he was, that would hold little significance to the Book of Law.