Without actually reading the whole post, my thought is that attractive women don’t join fringe movements. After all, good looking women gain so much benefit from the status quo, why would they want to change anything? That’s why at the Libertarian party or at an atheist rally, all the women in attendance are ugly, if you see any women at all.
So if a movement of any sort has hot babes in it, then this means that it is somewhat mainstream and not merely a fringe movement. And of course, a mainstream movement has a much greater chance of success than a fringe movement.
(Steve Sailer brought this post to my attention this morning, and he has a depressing comment about how the Muslim birthrate in Lebanon exceeds the Christian birthrate.)