To be fair, that's not what Protestants believe. This thread has a lot of misperception about other faiths, both from Catholic and Protestant posters.
Most Protestant believe that they can trace their Christian heritage all the way back to Jesus and his apostles, not to a monk in the Middle Ages.
Just like a tree with three powerful branches, the trunk belongs to all the branches.
After the split of the Eastern/Western Church, the trunk (universal church) gave rise to two branches. Later the Western Church split into Protestant and Roman Catholic.
To say that the Roman Catholic branch is the only church that can trace its heritage back to the First Century is not a Protestant believe.