Okay, here is the clear difference: All religions that have their origins in the Reformation, which includes the teachings of John Calvin are considered Protestant. Ask yourself would religions X (ex

resbyterianism) exist at all if not for the Reformation? If the answers is. “No, if not for the Reformation religion X would never have been,” then = Protestant.
On the other hand, how many of us Catholics wring our hands over the Borgia Popes, or the corruption that led to the Reformation? Or the Inquisition, or the Fourth Crusade?
************As to this, Catholics do not just wring their hands over these issues. These things are talked about, confronted, lamented over,and argued about from members, writers and leaders in the Catholic Church. The Vatican has even issued statements on the Inquisition and members of the Catholic Church had openly given their opinion criticism of such statement. Unlike Protestant religions that have adopted the Larger Catechism that makes it a sin to rebel and have contempt for superiors, no such rule exists in Catholicism. Very few Catholics will deny the corruption of the Catholic Church that angered people into the Reformation, or atrocities of the Inquisition and Fourth Crusade. Very few Catholics will side step, deny or attempt to re-write history on these matters. We know the faults of our own church and we do not deny it. So we do much then sit and wring our hands.
I wonder how many times people have that conversation about Catholics and come to the same conclusion? I wouldn’t feel such a generalisation or reductionist attitude of complex historical or theological issues was helpful in either case.
As to this, are you saying that people reduce the origins to Catholicism to…? The historical truth is that if King Henry the VIII had never wanted to divorce Queen Catherine and was content with Princess Mary, the Reformation never would have had political and financial backing to be propelled and give rise to the number of Protestant religions of today. That’s not reductionist, it’s a major point in the history of Western Civilization. If you can make the case that without the support of King Henry VIII and his break from Rome that the amount of Protestant members would be the same today then please be my guest.