Generally speaking, I think *they* could agree that a proscriptive law makes inaccessible some sort of personal liberty. There has never been a successful sustained government that did not do this. And since the absence of government, anarchy, is as bad or worse than having no freedom at all, tradeoffs are definitely necessary. Let us agree that, some problems aside like Campaign Finance Reform shredding the First Amendment, under the status quo individual liberties are sufficiently sancrosanct. Within that framework, various political forces will advocate various laws including proscriptive ones - in all cases, it will be argued (sometimes speciously) that a citizen's ability to pursue happiness is best served. These questions can never be settled and will forever be the subject of politics as long as the republic shall exist.
All that said, most policy preferences of social conservatives can definitely be argued in a way that would deflect your charge.
My point is that many social conservatives are so attached to their ideology that they cannot even *see* the truth of what I am saying.