The logic here seems to be: If there were a cure for baldness, barbers would know about it. Barbers don’t know about it. Therefore there is no cure for baldness. Modus tollens.
But the real gem is this quote: “Some are born bald. Some achieve baldness. Some have baldness thrust upon them… The born bald usually get over it and live to get it again.” Sage words.
IF YOU ARE BALD YOU’LL STAY BALD: That’s What a Tonsorial Artist Says and He Always Has His Reasons Therefor (PDF)
From July 24, 1910