Actually in production of textbooks for Kindergarten to 6th grade — elementary arithmetic, geometry, algebra, etc.
(quite ironic given that the last formal math class I took was in high school in 1967)
But I suppose to the old sayings
“If you can’t do it, teach”
and
“if you can’t teach, teach teachers”
we could add
“If you don’t like kids much, write curriculum”
I liked your explanation.
Cazalea aka ExcelMathMike