He says that most CEOs suck at technology, but really doesn't answer the question why. The answer is that during the time the executives were cutting their teeth in the industry, technology was not important. For most companies information-based technologies (not IT) were mostly backroom operations, payroll, accounts receivable, and the like. The keys to running the company were other things: sales marketing, finance, manufacturing. The skills that evolved into internet thinking were of little value. Fast forward 20 years and the key skill for a CEO is navigating the company is a sea of information, where the end customer probably knows more about the position of a company than the CEO does. They aren't prepared for it. Their cronies aren't prepared for it. Their boards (more of the same) aren't prepared for it. Even worse, the people who are prepared for it aren't even working for them.
The author works for a record label. This is the inside view.