This person clearly doesn’t know what he’s talking about and has completely ignored the fact that American schools try to educate one of the most diverse populations on the planet. The students come from homes where they speak hundreds of different languages, have totally different cultural values (including how their home culture values education), and where many come from very poor families who live in crowded conditions in crime-filled neighborhoods.
The changing demographic in the U.S. is largely (almost entirely, IMHO) responsible for decline of student performance over the years. Show me another country and school system with our demographics, and let’s compare how we fare then, shall we?