That's not what it says at all. He states that the 60s economy is still dominated by technologies that pre-date 1913. He even specifically cites the economically dominant technologies, instead of the vague assertion, "I'm pretty sure ...". He particularly notes aeroplanes and computers as being invented during that period and can be expected to have enormous economic impact. Which they did, but hadn't by that point. The same with television.
Looking at the rest of your comment, I kind of think you should delete and reread the article. Every criticism is incorrect or unsupported - like the MIT crack. He's clearly talking about the "thin client" approach to providing computing - he was wrong, but it was not an unreasonable supposition to make.