"I'm Catholic, but fuck the current Pope" actually has a name: sedevacantism. It's closely related to the concept of an antipope, which sounds scary and badass but essentially just refers to someone who isn't the Pope but is followed as if he was.

Hating shitty popes is a tradition as Catholic as any other. Catholics never reform or break away, they just stop listening to the asshole in the big hat for a while. Based on my personal experiences, more Catholics currently qualify as sedevacantists than not.