That still has nothing to do with alternative math, but teaching.
Math teachers need to know (1) math; and (2) how to teach it.
The argumet is that this falls into the second category.
I am not claiming to have read any evidence that it is effective, or even that there is any. I do think this shallow dismissal is improper.
That sounds a bit unfair, especially considering that anyone who would seriously try to provide such evidence would probably commit a career suicide, by being called a racist and cancelled.