>>54721658In most religious movements, you have a large and genuine majority at the bottom. Go further up, and it gets muddled. You had a group of nobles who set out with big dreams, and managed to make good on them. However, then they realized they had control of a rich, exotic land which would score them wealth and prestige.
So rather than return the land to the Byzantines, who were the owners before the Muslims, they kept it. And rather than remain united and ensure Christianity was protected, they squabbled over land and money, often times allying with just-as-amoral Muslims against one another. The greedy mercenary types would win out, thanks to being pragmatic, and so the Crusades went from something pretty cool to the raids of ambitious soldiers.