Why has the image of tax-supported public schools looking like and operating as factories stuck?

In an earlier post, I traced the history of the metaphor since the early 1900s and its 180-degree switch from a positive to negative meaning. Over the past century, the metaphor of school-as-factory has served the interests of two sets of perennial reformers (yes there is a third group that borrows from each side but I will stick with the two major groupings).

The Incrementalists

There are reformers (e.g., policy elites, practitioners, parents, researchers, and donors) who see the age-graded school and its standardization of curriculum, instruction, and student behavior in need of improvement to make it work as it was intended, particularly for poor and minority students.The purpose of schooling is to prepare the young for a demanding and ever-changing workplace and future civic duties.

Former U.S. Secretary of Education, Arne Duncan made that…