No, the physics is the same, it's just US engineering that's inferior. Show me the law of physics that states hypersonic vehicles can't have high lift to drag ratios - which of Newton's laws does that one follow from?
Let's be careful. Comments like that are often made about Chinese engineering and we know them to be wrong. The HTV-2 effort was 11 years ago! Much may have changed and blanket statements are rarely a good idea.