Nonsense, I do not find it difficult at all.
Libertarian philosophy concerns itself with how men govern themselves and the proper role of government in a free society. It defends rights.
It leaves moral judgements to the individual and God. And that is what drives authoritarians crazy.
That statement is demonstrably untrue.
Murder, rape, robbery, burglary, fraud are ALL morally wrong. Moreover, they violate some else's rights and are thus the fit subject of law. BTW, I consider abortion murder.
I personally find homosexual relations immoral. It's bad for the people who engage in it, in my opinion. But no one's rights are being violated. Thus it's NOT a fit subject of law.
There's no problem making absolute moral judgements holding to a libertarian philosophy.