MBA is a graduate program. I was discussing high school and college undergrad.
I doubt there are many investment bankers on Wall Street using calculus as a routine part of their job, whereas statistics and probability come into play frequently.
The point is that high school should prepare children for the future and provide the tools needed for success.
Calculus has never been required for graduation, but for students on an accelerated path, it is an important head start into the level of study they will encounter.
High school should prepare students to succeed. In some cases, success doesn't require higher mathematics, in other cases it is required.
What purpose is there for high school if not to prepare for the future?
Now I place little credence on what China says, they are the "Doc Dutch" of nations - anything they say is likely a lie. Still, Japan, Singapore, and South Korea all outperform the USA in math and science. That is not where we should be. And we are DECLINING, rapidly.
We put one of the highest percentages of GDP into public education in the world, and the return on that investment is abysmal at best. Crap like in the OP is a significant factor as to why America fails in education. The teachers unions are behind much of this.