Society, through the democratic process, evaluates behaviors and then decides if they advance the public good...We put it to a vote. One side wins. That is democracy. It is not liberty. Do you consider yourself a small d democrat? Your theory defines it.
Prohibiting all actions that do not in themselves advance the public good is the ultimate in collectivism. It surpasses communism in its potential for control. A people under such a system could not truthfully claim to be free.
You'd be surprised, freeee, at how much Marxism and Randian libertarianism have in common. First: flawed view of human nature. Libertarians believe people are naturally good, i.e. "Why shouldn't everyone have a right to have a nuclear bomb? Who in the world would use it for evil purposes?"
And so on.