The dude literally invented Extreme Programming and was the first signer of the Agile Manifesto. He's forgotten more about software development than most people on this site ever knew.
Someone's accomplishments don't make them incapable of having bad opinions and being wrong. Cults of personality are harmful to progress. Opinions should hold the same weight and be held to the same scrutiny regardless of who voiced them.
Seems to me that his core competency is in managing a software team, not developing software.