[yt]https://youtu.be/CkTBf7HW_rg[/yt]
In the past, the Pope was arguably the most powerful man in Europe. The Papacy was imbued with pomp and prestige and majesty, and even as the Pope became the Prisoner in the Vatican and eventually a spiritual leader alone this majesty remained.
People like the Pope for the same reason they watched Will and Kate's wedding - Americans have a fascination with bejeweled royals.
Pope Francis in particular is exciting to many people because he represents a change in the Catholic Church. Despite him upholding their archaic views on abortion and gay and women's rights, he seems more liberal than Benedict in other areas and that's appealing to a lot of people. He apologizes for sexual abuse by priests and focuses on the poor. People like that.