Replaceable parts was the greatest industrial innovation in the history of the world. It’s the single most important reason that millions of people can afford refrigeration, stoves, lightbulbs, TVs, cell phones, cars, and everything else in the modern world. Without replaceable parts these things would only be luxuries for kings and queens.

The problem of engineering departments being “glorified parts replacers” is a social problem: elite overproduction. Society simply does not need millions of engineers (or lawyers or historians or urban planners for that matter)!