A lot of stuff we take for granted are either accidents of history, or powerful counter-reactions to the accidents of history.
There is a practice, and it turns out to be bad. Mild discussion of the virtues and vices would, in a world composed of Asimovian robots, be sufficient to update the practice to something better.
But that's not how humans work! Typically an existing practice is only overturned by the loudest, most persuasive, most energetic voices. And they have to be. Humans don't come to the middle by being shown the middle. They come to the middle after being shown the other fringe.
So a generation changes its mind and moves closer to the new practice. Eventually, that is all the following generation has ever heard of. The original writing transforms its role from mind-shifting advocacy to the undecided to being Holy Writ. The historical context, and with it the chance to understand the middle way that had to be obscured to find the middle way, is lost.
My previous role was as an engineer teaching other engineers an XP-flavoured style of engineering. I often referred to our practices as "dogma", because we are dogmatic. But if we aren't, less learning takes place. Dogma is most instructional when someone later finds its limits.
When I was learning to coach weightlifters, I was told something that has always stuck with me: "As a coach, you will tell trainees a series of increasingly accurate lies". You can't start with nuance. In the beginning, it won't work.