All this because some people didn’t believe in God the same way as they did?
The fury at the Catholic Church was bottled up for hundreds of years, and then Luther came forward with two HUGE developments:
1. A version of the Bible written in the common language - German - instead of Latin. The Luther Bible was one of the forces that set off the firestorm in Germany - people realized upon reading the Bible in their own language, translated by a man with Luther’s credibility, that they had been lied to, and lied to in a huge, lasting way.
2. After the Reformation started, you were going to see all manner of factions and schisms start, as doctrines of theology got going. Once it was no longer impossible to question the manifestly corrupt Catholic Church, it was no longer impossible to question anyone, including Luther.
Lastly, after the atrocities perpetrated by the Catholic Church, there was serious payback coming. The Church earned it, so they got it.