geography can be given credit to the break up of the church's authority. Protestantism, Lutheran, State Church's, can all give some credit to the difficulty of a very far away strange place attempting to control the dogmas of the entire known civilized world.
The other major factor is that the strange place was corrupt.
Because eastern orthodox venerates saints and believes in works which some Christians are totally against. They also call the eastern orthodox prayer rope a blasphemy just as they would the rosary. But I have no problem with it. The only thing I disagree with in the Ctaholic and Orthodox Churches is that you have to be baptized in their Church to go to heaven.
My guess would be that Eastern Orthodoxy didn't offer them the freedom to interpret scripture as they saw fit.
Luther and those who supported him, wanted their own brand of religion. One in which each individual can call the shots, and God becomes relative, made in the image and likeness of each person and their particular likes and dislikes. Eastern Orthodoxy didn't offer that.
Because the Eastern Orthodox Churches are very similar to the Church of Rome, except that the hierarchy is somewhat different. I also think it would have made Henry VIII a saint!
As many already said, the reason behind the Protestant Revolt wasn't just because of what some priests were doing. It was mainly because people like Luther and Calvin wanted to interpret the Bible on their own and decide what they wanted to believe and what they wanted to throw out.
Eastern Orthodoxy is still considered a valid part of the Catholic Church because they still hold to the Truth of Jesus Christ. Their Sacraments are still valid (because a large group of bishops and priests broke off for various reasons, but were not looking to change the fundamentals of the Faith) and they remain true to Christ.
Calvin wanted to change the Faith into an idea of Predestination. That only a certain amount of people were going to enter into Heaven and no matter what they did (good or bad), they would still go to Heaven. Those who were not predestined for Heaven were sent to Hell no matter if they lived upstanding moral lives, gave money to God and remained faithful to God their entire lives. Calvin's belief was that Jesus died only for some people, not all.
Luther wanted to (and did) change the Bible and core beliefs of Christianity. He stated that polygamy--for men--was not against the Bible and he would not turn away any man who wanted to marry another woman if he kept his first wife. He also removed books, added words and changed many core beliefs.
This is what the Protestants really wanted. It wasn't to get away from the Pope, it was to get away from the authority given to the leader of the Church by God so they could do whatever they wanted to and believe whatever they wanted to.