I much agree with the article on how to deal with individuals arguing from a mistrustful position, but your insight that this doesn't deal with a problem on a societal level makes sense.
What has caused so much mistrust on a broad nebulous scale? Civil war and slavery are not unique of course, and every nation carries its traumas of war and disaster. But the American collective psyche is unique in relation to a series of events starting in the late 60s that seem somehow connected - Kennedy, Watergate, Vietnam, Chile, Cuba, Afghanistan, Iraq, 911, Snowden...
What links these is a strong perception of betrayal by government that has failed in its duty through corruption and preference for private power interests.
It is to the credit of American people that they have courage for sceptical introspection and aim to hold government to account.
But something else has happened. Now, because the US plays such a big role in replication of culture, a paranoia, which is practically dyed into Hollywood output (X-Files, Enemy of the State, JFK etc) reaches around the world.
Somehow this needs treating separately from there being, in reality, in actual fact, both an increase in corruption due to global financialisation and technology, as well as a much greater awareness of extant, quiescent skulduggery due to the internet.
And there is one more layer to add now. That some agencies in the world, deliberately fanning the flames of mistrust and division for political gain, have their power amplified by digital technology.
One has to wonder, what event would restore trust in competent and benign government? Is there such a thing as therapy for a whole culture?