Certainly this was true in the beginning - but Luther did come to think that the office of the Pope was perilous regardless of who occupied it. From Luther’s letter to Leo X:
"Therefore, Leo, my Father, beware of listening to those sirens who make you out to be not simply a man, but partly a god, so that you can command and require whatever you will. It will not happen so, nor will you prevail. You are the servant of servants, and more than any other man, in a most pitiable and perilous position. Let not those men deceive you who pretend that you are lord of the world; who will not allow any one to be a Christian without your authority; who babble of your having power over heaven, hell, and purgatory. "
Certainly the current Pope, is a “servant of servants” but the Catholic church’s instance that it alone can “allow any one to be a Christian” is precisely where, in my opinion, it still goes too far. We Lutherans would say that is is God who allows us to be Christian.
Now, please realize that my objections are not bitter - I love my Catholic friends, and I appreciate the Catholic Church as it is a light to the world. The godparents of my third child are Catholic, and if any of my children became Catholic, I would be content.