I was a maths minor and dropped out of a MSc in Applied Maths. I took many courses that would be considered advanced by most, such as Stochastic Calculus, Partial Differential Equations, Multivariate Statistics, Time Series Econometrics, etc.

But I left academia over a decade ago, and have never used any of that. I have, however, used a few things above 8th grade maths, such as linear algebra, regression analysis, and some basic numerical analysis. I used once a FFT.

All in all the author is spot on. And I believe an advanced degree in maths is not a legitimate requirement for anything but a handful of positions, and most of those aren't particularly desirable.

I still remember fondly my days studying Baby Rudin, though. Definitely one of the courses that made an impact in my education. But in hindsight, it's been as useful in my career as my study of Latin.