This is exactly the fallacy he is addressing. Math = rigor, so clearly the discipline which uses the most math is the most rigorous, right? But actually math is

This is exactly the fallacy he is addressing. Math = rigor, so clearly the discipline which uses the most math is the most rigorous, right? But actually math is only useful when it is based on a useful model of reality. If the underlying assumptions are unfounded or faulty, then math does not help you at all.