What was that George Burns joke? Sincerity is everything, learn to fake that and you've got it made. So is this an extension, destroy the value of sincerity/a

What was that George Burns joke? Sincerity is everything, learn to fake that and you've got it made. So is this an extension, destroy the value of sincerity/authenticity instead? The letter seems like little more than a pretty intense bout of literary critic navel-gazing.