In the midst of the article the author states:
This is essentially the story of public higher education over the last
thirty years. Diplomas are, of course, not apples. But they are more
like apples than colleges like to pretend. In particular,
highly-profitable lower division courses in common subjects like
Economics, Calculus, and Psychology have similar curricula at most
colleges and rely on many of the same nationally-marketed textbooks.
They are often taught by people with no formal training in teaching.
These courses are, in the education context, commodities.
The last statement is typical of the union backing left wing of the Democrat Party. Namely that only by being trained to "teach", aka being in a union, can you teach. Nonsense! Universities often use their best faculty to teach the under graduates, at least the top universities. Yes they have TAs and Instructors who are PhD candidates but hospitals also have residents.
A hospital resident is a licensed physician, albeit one still in training, who is legally allowed by the state to practice, not by a union. A TA may very well be a PhD candidate, one who has a Master's Degree and has passed doctoral Board exams demonstrating exceptional competence.
Now a union high school teacher has allegedly learned teaching methods but may very well be clueless as to the subject matter. And worse is in a union. Imagine Harvard becoming GM! It may also go bankrupt. In more ways than one.