Steam plague

The steam plague was the name given to the pandemic that, along with the Bright Way's stagnation toward orbital flight, resulted in the Shakeoff that formed Neoshamanism and Atavism.

With the widespread adoption of steam engines, and with them, trains and steam ships, long distance travel became much more common. This allowed a particular viral disease to spread rapidly, killing millions in short order. However, the yinrih didn't know about germ theory yet, and assumed the disease resulted from exposure to the exhaust produced by these steam engines because it seamed to spread outward from train stations and seaports.

The research monks were the entire scientific establishment at the time. While they had excellent knowledge of anatomy (you have to know these things if you want your test pilots to survive crashes) they were completely ignorant of microbiology, and were still operating on what was essentially miasma theory. Their woefully inadequate response caused people to question whether it was right to hyperfocus on getting to the stars. Maybe there were other areas of inquiry that deserved attention. It's not that these areas were totally ignored, or that they were treated as anathema, but rather that they were unimportant compared to fulfilling the Great Commandment.