A Roman Catholic priest told me that. The priest also explained to me about how all of the protestant churches not only dislike Catholics but they are in war with each other. Each protestant congregation you see is fighting with all of the other protestant congregations on the same street and in the same town.
From the web:
Luther was unhappy about the diversity appearing among the Protestants. He was no defender of choice in religious conviction. He believed that God had spoken clearly and that no excuse existed for deviation. Truth for Luther was not a matter of interpretation. Truth for Luther was absolute and people who strayed from that truth were in error. http://www.fsmitha.com/h3/h18-eu.html
Even the diversity of protestants during the reformation was not that great. The only real difference between the theology of Luther and Calvin was over the sacraments, primarily the Eucharist. As a matter of doctrine I see little difference between Augustine, Luther, Zwingli, Calvin and Knox.