Because the writer must be a participant in the scene, while he's writing it — or at least taping it, or even sketching it. Or all three. Probably the closest analogy to the ideal would be a film director/producer who writes his own scripts, does his own camera work and somehow manages to film himself in action, as the protagonist or at least a main character.
Nixon represents that dark, venal and incurably violent side of the American character almost every other country in the world has learned to fear and despise.
But our trip was different. It was a classic affirmation of everything right and true and decent in the national character. It was a gross, physical salute to the fantastic possibilities of life in this country-but only for those with true grit. And we were chock full of that.