False a novelette is longer than a short story, shorter than a novel.
If this is asking for a personal opinion, then no. I do not believe there is any relationship or connection between sanity and intelligence because someone’s mental state or background doesn’t define their intelligence or thinking patterns. Some studies done over mental disorders such as BPD (borderline personality disorder) have found sufferers to be more intelligent and, ironically speaking, happier than the average person.
"Grass" is actually a poem that was written by Carl Sandburg. This is a poem in which he has published right after the World War I which is in the year 1918. Based on this poem, you can sense an unforgiving tone in it. Therefore, I can say that the attitude that the author expresses is "anger". Hope this answer helps.