Because Popes can be in a state of mortal sin and go to hell like everyone else. They can even renounce the faith altogether. And people in a state of mortal sin and in hell are a lot farther from God than people who are in a state of grace and in Heaven.
There are people all over the Earth who believe all sorts of untrue things. That does not make them valid.
I agree with you that there is too much "celebrity fanfare" surrounding the pope. On the other hand, undue media attention and so-forth can be turned around and used for good purposes, such as proclaiming the gospel. If the world has made the pope a celebrity, then the right thing for him to do is to use that celebrity to try to bring people to Christ, in much the same way that some other celebrities like Tim Tebow do. If he simply basks in celebrity for its own sake and for his own pleasure, then he loses his reward in Heaven.
People get excited to see many people such as music artists, sports stars, etc. Doesn't Joel Osteen packs in 50,000 or so people every Sunday? That does not have to mean that the people who want to see them think that they are closer to God. Maybe they like sports. Maybe they like his sermons, or maybe they think that the are interesting or good people to meet. When the Pope visited DC a few years back I was among the people who wanted to see him, for example, but I do not believe that because he is pope that makes him closer to God than anybody else.
I think part of the problem that many people have with the Catholic hierarchy, is that they view power and authority within the Church in the same manner as they view power and authority in the secular world. But the pope is not given authority so that he can lord over people. He has power in order to be a servant. Any pope who abuses that power to serve himself, may end up in hell just like the rest of us. And any pope who puts that power good end, by the grace of God, may end up a saint. Just like the rest of us.