What's so holy about a human being?

Eugene Shubert

Catholics call the reigning pope "The Holy Father." Protestants have always taught that there's nothing sacred or holy about the will and whims of a pope or the man himself. Where do Catholics get the idea that the Apostle Peter or an elected pope should be thought of as holier than any other Christian?

http://www.everythingimportant.org/gospel/

I get the impression from Revelation 13:4-7 and Protestant history that medieval Catholics thought of the pope as holier than all other Christians. Isn't it true that Catholics still believe in papal infallibility? Isn't that a level of holiness that is above the other Apostles and absolutely unattainable by the greatest Protestants?