The poet was Walt Whitman. For a millennium and more, even the best minds have made some strange predictions for the arts. Shaw himself had some unusual opinions, especially of Shakespeare.
Criticism can be a matter of political or social taste.
Norman Mailer once confessed he just couldn't think of any woman writer he admired. Mary McCarthy's label for A Streetcar Named Desire was A Streetcar Named Success, her primary objection that the play was too popular. Contemporary music has inspired some interesting, if regrettable, opinions. Rejection letters alone offer a nice history of unfortunate judgment. The girl was Anne Frank.