As the last major profession organized on the medieval guild model (masters, journeymen, apprentices), academia is now going through an Industrial Revolution of its own. In the 17th-18th century, the guild system fell apart completely because the proliferation of journeymen meant that few would ever become masters, although the system was based on the assumption that they would. The result was the proletarianization of the journeyman class and the disappearance of the independent masters. This is precisely what’s happening in academia now. Any distaste we may have for this process is just a form of misplaced bourgeois aspirationism.
From Greg A (of Slawkenbergius), buried in the comments of an old post.