If these have been legtimate popes, then the Church has suffered a black eye from which she can never recover, and the gates of hell would have prevailed against the Church. It's possible, so you say, for the Church's Magisterium and public worship to go corrupt for half a century. It's OK for Catholics to effectively ignore the Magisterium and second-guess anything taught by the Church short of something that clearly has the notes of infallibility. What then is left of Catholicism? When the next group of heretics comes along, couldn't they just claim, "ah, well, the Church is just in error about this." How do we know the Modernists weren't right after all in disobeying St. Pius X? There's no guarantee apparently that Rome can't be gravely mistaken about faith and morals. Why weren't they within their rights to second-guess the Magisterium? You guys who promote this idea destroy the Catholic Church.