The “Old Catholic Church” was never more than a splinter group. As for Pio Nono’s motivation, it was the shock of realizing that Italian Liberals were fanatics who would stop at nothing—and were liars. Jokingly he once said that he and Garibaldi were the only honest men in Italy.Honesty was certainly not one of Pius's traits according to many Bishops of the time.
* “Other bishops, like Bishop Henri Manret, openly called Pius IX a liar, so the charge was not at all unusual or suspect.”
* “Cardinal Gustav von Hohenlohe told a friend:” ‘In my entire life, I have never met a man who was less particular about the truth than Pius IX.” “He never admitted to the things he had done in his efforts to have infallibility declared an official Church dogma.”
* “Bishop Felix Dupanloupe wrote in his diary: "I'm not going to the Council anymore. The violence, the shamelessness, even more the falsity, vanity, and continual lying force me to keep my distance."
* “Bishop Lecourtier from France, who was so discouraged that he threw his notes into the Tiber river and simply went home only to have his bishopric taken away for his trouble, complained:
http://www.catholicshaveachoice.com/Against%20Papal%20Infallibility.htm
So now you know that popes have people who hate them. And for the usual reasons: they have agendas of their own.