R&D want to “limit the state to securing conditions for the possibility of moral action.” (50) But moral action is possible under any non-hellish conditions. It doesn’t even need the state. A man can obey the injunction “You shall not steal” even if the state is not tasked with punishing thieves. It’s true, of course, that punishing thieves helps.
Now what if Rothbard were asked why the laws shouldn’t go beyond “criminality and aggression”? I’d reply in his stead: it’s because the proper role of violence is defense, enforcement of judicial sentences, and punishment, not moral uplift.
It’s not that Rothbard was “indifferent to the promotion of virtue”; it’s that he figured that violence was not an appropriate means to promoting virtue, and in EoL he focused on those things for which violence was, in his opinion, useful.
Mises explicitly argued that the “liberals do not disdain the intellectual and spiritual aspirations of man. On the contrary. They are prompted by a passionate ardor for intellectual and moral perfection, for wisdom and for aesthetic excellence. … In their opinion the foremost social means of making man more human is to fight poverty. Wisdom and science and the arts thrive better in a world of affluence than among needy peoples.” (HA, 154-5) He held that liberalism fought poverty with unparalleled efficiency.
Maybe R&D are not mentioning the right liberals.