Why does Nunberg report from an "Olympian point of view"?

(The Decline of Grammar)

Shauna has collected a variety of sources for her research about charlie chaplin’s impact on american cinema. in performing her preliminary evaluation of each source, shauna should-thoroughly review and examine the content.-perform a quick search to determine the author’s reliability.-check whether the author agrees with experts on the subject.-decide whether it will be useful in her final essay.