I suggest you read "Goodbye, Good Men: How Liberals Brought Corruption into the Catholic Church" by Michael Rose and "Amchurch Comes Out: The U.S. Bishops, Pedophile Scandals and the Homosexual Agenda" by Paul Likoudis for further insight.
If the choice is between confessing to your parish priest who is openly living with his boyfriend or a priest who belongs to SSPX, there would seem to be "just cause" to opt for the latter. Faculties or not, perverted priests are OBJECTIVELY not trustworthy to hear one's confession. The sad truth is that when obedient, orthodox priests are thin on the ground, Catholics may be forced to make such choices. This is where Can. 1335 and prudential judgment seem to apply.
I can see where it would be difficult to find someone in that the only alternatives are far from where you live or something, particularly in more rural areas so maybe there are cases that fit the bill.
It just seems to me that more often than not it's a question of convenience and personal preference rather than necessity, exactly same criteria Cafeteria Catholics base their decisions on. Erring on one end of the spectrum for the same reasons others err on the other end of the spectrum, if you see what I mean.