The most compelling tenet of the social-democrat system is the injunction to help those in dire need. The libertarian would admit the virtue, but would ask why it is more virtuous to force other people to help than to simply help. But I have a different question.
Why does the social-democrat feel it necessary to suspend the free markets to help those in need, instead of just helping them directly. If people need health care in their time of need, why not just pay for it. Why do we have to turn the whole sector into a dysfunctional thicket of misguided incentives? If every child should be guaranteed education, why don't we just pay for him to go to school, or to become educated some other way.
Maybe it's because as messy as the socialized systems become, they at least settle into some sort of homogeneity. Health care becomes a thing, a commodity. Otherwise the problem of distributing it fairly would become wispy and untenable. But health care should not be a commodity, and education should not be a commodity. They should be set free to blossom and to heal the world, amongst all other human enterprise.