The point of the article, as I read it, is that 50 years ago there basically weren't instructors: very few college/university classes were taught by anyone othe

The point of the article, as I read it, is that 50 years ago there basically weren't instructors: very few college/university classes were taught by anyone other than (tenured or tenure-track) professors. That model has been increasingly abandoned in recent years: "we discard[ed] the idea of college faculty". If there ever was a reason that university teachers deserved tenure, that reason has eroded or been outright cast aside over the past few decades. The author of the article thinks that's a bad thing, and I tend to agree.