This would be because they don't have them. The protestants make no claim to authority beyond their own ability to understand the Bible. I would be curious on the Catholic take on this though, for they claim some kind of authority.

I hear the priesthood question a lot. Well, in biblical times you didn't go to a school and get a degree and were then made a priest. It was past on by the laying on of hands by one with the proper authority and priesthood to pass it on. That is the case for the higher priesthood, at least, except when Jesus bestowed it. There's no scriptural reference showing that Jesus had to lay hands on anyone, he just verbally gave them the priesthood, first three apostles, then the twelve altogether, but all other instances it was past by the aforementioned means. John the Baptist held the Levitical priesthood, Jesus and the apostles held the Melchezedek priesthood. Now, people have problems with the Aaronic priesthood, which is the Levitical priesthoods equivalent, but there's a major difference. The Aaronic priesthood is a stepping stone, a lower form of the higher priesthood, therefore not passed by blood. Jesus is the Highest of All High Priests in the Order of Melchezedek as Hebrews said, but is by no means is he the only or the last, there's no scriptural basis for that, yet no other church has an actually claim to this priesthood. There was such a blatant apostacy and falling away from the truth, and the Melchezedek Priesthood was lost for a time. And so, yes, we bear the priesthood of god, not the priesthood of man. For simplicity's sake, we Mormons treat the Levitical and Aaronic Priesthoods the same way, but the levitical priesthood was passed from father to son in the tribe of Levi, and the Aaronic does not work that way. But the Melchezedek priesthood has all the same powers as the levitical priesthood, and much more. Therefore, the church has both these priesthoods. God gives us a little authority before he gives us a lot of authority, so he can test us and we can test ourselves, learn, and make ourselves ready. Now, I think that pretty well explains the priesthood point. If it was done one way in ancient times, and the bible says nothing or it changing, then why should we believe that it has? Just because a few people say so? That's not very scripturally sound. So obviously, after the priesthood was taken away there had to be a restoration, and if there must be a restoration of the Priesthood to restore Christs church in this last dispensation, then their needs to be a man of god leading it, else it might fall again into apostacy. As for why other churches can't claim having them, well, after all I said above, that should be pretty obvious. Long before the Catholic Church was even founded around 300 ad, the proper means of passing on the priesthood was practically forgotten, and when it was remembered, it was even less often observed. And so if the apostles ever appointed any priests of Melchezedek before they died, then all those priests and any after them were long gone. Hense they have no one with the proper authority to give this priesthood, hense they pretend they don't need it. They act as if they have this golden priesthood because some school gave them a diploma.

It's probably in the version that hasn't been released yet