I firmly believe that even if a Bishop is a bad bishop and a Pope is a bad pope, they still are part of the Hierarchy of the Church and their authority is given by God, not earned through personal sainctity. When they act inside the limits of their rightful authority, however, they shall be obeyed. We are now in a very difficult moment in the History of the Church. Never did heresy get so widespread in the Church, not even in Arian times. It is even worse, because Arians had a Doctrine, albeit false, while Modernism hasn't.
Modernists just believe that there is nothing to be believed.
The core of Modernism is disobedience, disobedience to Reason, to Tradition, to the Scriptures and to the Magisterium. If the priest is a bad priest, go to the Bishop. If the Pope is a bad Pope, obey his rightful orders and hold fast to what the Church has always taught. Once you leave the Church, which is visible and has a visible Hierarchy, you are bound to Hell. If the good Catholics, if the ones who want the Doctrine of the Church upheld, the ones who want the Deposit of the Faith transmitted to the new generations, decide to give up and stablish a makeshift Church with an illicit hierarchy, they are going against the Church and in fact becoming Her enemies.