What was a major reason that many local german leaders became Lutherans on the 1500s?

They shared many of the critical views of Martin Luther regarding Catholic dogmas and practices. They could not accept the practice of indulgences and papal bulls, that is, the idea of getting forgiveness of sins for money. They were shocked by the scandalous and immoral conduct of many Catholic top officials. Besides, Protestantism was adopted as a the official religious practice by several German princes in the 1500s, contributing to its spread and strengthening.