It isn't the most important thing, but it does provide a simple illustration. Describing that letter as "scathing" was a choice. It could have been described in plenty of other ways. More generally, a reader stationed on one of Saturn's moons who only knew about Our Big Wet President from what he or she read in the New York Times would not have a good sense of just what the soppy wet fella was really like, or what was really happening in the country. And if they aren't there to inform readers... what are they for?
