Why did martin luther want the reformation of the catholic church

Because the Catholic Church was so corrupt and had made people believe that they were the gatekeepers to salvation. Very few people were able to read the Bible for themselves, they counted on the clergy to read and interpret it for the masses.

The Catholic Church had the religion set up as a money making and power brokering propostion. Luther was a German monk who was sent to Rome as a reward for his hard work, diligence and faith. When he got to Rome and saw the corruption of the sale of indulgences, of "relics" as well as the Pope's moral turpitude, he was shocked. The moment that cinched it was when he went to a "holy" hill where a believer would pay a fee to crawl up 100 stairs on his knees, saying an Our Father/Hail Mary on each which was supposed to guarantee that the person he prayed for went to heaven. As Luther crawled, he thought about why the stairs weren't packed with people and where in the Bible it said that this would work. It dawned on him that it was a money making scheme that went straight into the Pope's pocket.

Luther wanted to cut out the middle men and allow people to establish a relationship with God directly. Also he believed that everyone should be able to read and study the Bible for themselves. The Catholic Church fought against the encroachment on their wealth and power.