Not only did Martin Luther exhibit a boldness only seen once in a generation, he was also quite earthy. In terms of boldness, he stood up to the oppression and greed of his day, nailed 95 grievances against The Church on the door of Wittenberg Chapel in 1517 and stood firmly for his faith regardless of the personal cost.
In terms of earthiness, Luther believed he could drive Satan away with his own flatulence. He also never mixed words and was known for saying exactly what he meant.
He went against the common teachings of The Church, by insisting that it was bad form to force people to pay money for forgiveness of their day to day sins when the son of God had already paid for those sins in full. Luther was also not terribly fond of the idea that the Pope’s word could trump Scripture, thereby allowing the Pope in his infinite wisdom to create a new way of salvation apart from that already set forth by Jesus.
He also translated the Scriptures into German, believing that perhaps a God who would go through all that trouble to come to Earth as a human being might like for people to understand his message in their own native languages.
These beliefs set him apart from The Catholic Church and The Pope, but Luther was undeterred. He simply started his own brand of Christianity known as Protestantism. While it may have been a good idea at the time, it is quite possible that this new brand of Christianity spurred multiple fragments and sects which led to the modern day branding crisis that is the church.
What started with legitimate concerns of the unchecked power of the pope and abuses of power has lead to churches forming over absurdities like which type of bread to serve at communion and whether or not Jesus actually drank wine or watered down grape juice.
It is entirely possible that — were he alive today — the founder of Protestantism would believe that modern protestants protest too much about minor issues and not about issues of significant import.