I think the other piece the comment and the rejoinder miss is is: A PhD generally means you've done four years of work post bachelors, and some of that work was novel.

A PhD alone does not make someone an expert in most modern senses in software. The folks the author describes as "experienced" often have more than a decade of working software knowledge from after their education.

Casey Muratori has 30 years of programming experience. That's not a PhD, that's a PhD and then an additional 20+ years of experience.