This is just a consequence of the philosophically liberal metaphysics, anthropology, and resulting moral views and political orders they produce. Once you accept those premises, they act as a corrosive agent that can be deployed to dissolve all sorts of truths opposed to someone's conception of "autonomy" and "freedom" and you really have no defense as long as your thinking is subject to them. It's why the Right has consistently lost all sorts of cultural battles. They, too, are liberals - because we're all liberals, culturally - and as long as they remain so, their "reactionary" behavior will largely remain rooted in mere sentimental attachment to an imagined past rather than something intellectually substantive. Hence, why what falls under the label of "postliberalism" has a much stronger shot. It is an intellectual rejection of liberalism with intellectual substance that often draws on robust metaphysical and anthropological "alternatives" to liberalism, as it were.