Consider the world mid-20th-century that Hayek and a few others faced: Pseudoscientific, anti-humanist totalitarian hogwash (and worse) had caused a tide of blood to surge over half the world. The Renaissance and Enlightenment ideals of free inquiry and exchange were under attack from many fronts. Even the societies that had achieved greatness by embodying those ideals were turning their backs on them. Jeremy Rifkin didn't just happen by accident.
While it would be nice to believe that progress of the classic liberal, humanist and scientific programs is truly inevitable, I think it is dangerous to do so, because it cedes the energy of advocacy to the enemies of these agendas. Creeping statism, anti-scientific attitudes and cultural pessimism became dangerous because the forces that had propelled progress in all these things became complacent. The Renaissance and Enlightenment program of developing an integrated scientific world-view became a far from universal motivating ideal. Instead the corrosive mentality of deconstructionist post-modernism came to dominate in academia and began to seriously undermine the integrity of the scientific method on many fronts.
Transhumanism and extropianism are "daring" in exactly the same way that humanism, science and classical liberalism were "daring" when they were new. In historical terms (to say nothing of biological terms), these ideas are very, very new. Superstition and mindless submission to authority are in fact the "mainstream" of human history. Personally, I believe that failure to maintain an energetic effort to continue the progress we've had so far will result in a return to the norm of human history: If we don't work at being rational, we won't be, as a species; instead, we'll just be stupid with more powerful tools.