If you were really opposed, you would recognize that eugenics is the dominant ideology in effect today, and it would be target #1 of revolutionary organizing. It has to be, at this point, because that is where the people are at the moment. But, the movement as I understand it draws from intellectuals, because that's where the power really resides in the current system and those are the people who can actually fight a revolution. There is a fundamental divide between the intellectuals who would be in a position to wage a revolution, and the lower classes who bear most of the consequences of eugenics and capitalism, and the two are fundamentally at odds with each other. The anti-eugenicists can't build a material basis to fight with, at least not easily, because control of knowledge itself is paramount to fighting a revolution and to the everyday business of any industrial, technological society.