Terry Deary has said of historians: "They are nearly as seedy and devious as politicians..They pick on a particular angle and select the facts to prove their case and make a name for themselves... They don’t write objective history... Eventually you can see through them all. They all come with a twist."
Seems to me he's doing just that with this article and while I agree that the average person might not use much Trigonometry in daily life I wager the people who build the ships and planes and other such defenses for us so that we can be free to read whatever we please do. Not to mention the astronauts who did the experiments which led to many of our modern inventions and medicines. Just because the average person doesn't use calculus in their daily life doesn't mean that no one does and that it doesn't serve a useful purpose. I do agree that he doesn't seem to have learned much in school if he can make that sort of statement with a straight face.