This Article is a manifestation of Madison’s hope. Start with the reality that it seems quaint in retrospect to think that any of the Bill of Rights would be preserved absent the force of law. This is one of the great lessons of the Internet and the rise of Aggregators: when suppressing speech entailed physically disrupting printing presses or arresting pamphleteers, then restricting government, which retains a monopoly on real world violence, was sufficient to preserve speech. Along the same lines, there was no need to demand due process or a restriction on search and seizure on any entity but the government, because only the government could take your property or send you to jail.
Ben Thompson makes the point that during the time of printing presses and pamphleteers, when free speech laws were drafted, the threat to free speech could come only from one entity: the government (with its monopoly on violence). Thus, placing restrictions on one entity — the government — would be sufficient to safeguard free speech.