It has NOTHING to do with charity when it's a question of verifying your priest's education and ordination. That is called PRUDENCE and DUE DILIGENCE. You don't mess around with the Sacraments. How would you like to find out all your confessions were invalid? All those "communions" were just you worshiping bread, because the man you "hired" to be your priest turned out to be invalidly ordained?
Or how would you like to have 14th and 15th century problems (read your Church History) because your priest's formation/education was not worth a pound of rat dung? Why do you think the Protestant Revolt happened? I'll give you a hint: it wasn't ALL their fault. Priests were setting a horrible example with widespread ignorance, immorality, concubinage, and error quite commonplace. It was right after the Black Death, so there was a real priest shortage and a desperate need for priests. Many were tempted to ordain unqualified, untested, and untrained priests, for reasons of expediency. Sound familiar?
Priests were selling indulgences. Yes, they were. Actually selling tickets to heaven. They were NOT teaching the correct Catholic doctrine on indulgences; they were inadequately trained, and were horribly ignorant about dogmas of the Faith. This scandalized many who were then inclined to give ear to the protestant revolutionaries. After all, they were correct about the Catholic priests and selling indulgences. See how bad scandal is? See how bad ordaining unfit men to the priesthood is?
That is why it is GOOD to demand to see a priest's credentials (seminary formation, who ordained him, when -- docuмents and proof). A priest is a PUBLIC MAN. His seminary formation and ordination are PUBLIC BUSINESS, not "the priest's own private business". You aren't butting in or imposing when you ask for evidence about his ordination. That is why ordination ceremonies are always public. They are matters of public record, and affect the public more than anyone else.
It's not just about knowledge either. It's about FORMATION. During a seminary formation, the candidate is exercised in various spiritual duties on a regular basis. He is tested and tried, and some candidates leave because they can't handle the discipline, celibacy, prayer life, studies, obedience, etc.
Sure, living through 6 years of regular life (daily Rosary, Mass, and spiritual duties including daily prayer, meditation, divine office, etc.) is no GUARANTEE of future success, but it's a good and necessary start!
And apparently the Church agrees with me, because the Church, and the Council of Trent (whence comes our precious Tridentine adjective) declared that henceforth, all priests WILL be trained in "seminaries".
So any modern-day Catholic, Trad, who dispenses with this requirement, is not very Tridentine, even if they claim to love the Tridentine Mass.
One of the few things I agreed with Fr. Cekada about: A Tridentine Mass needs a Tridentine Priest. You can't cling to Trent when it comes to the Mass of all Times, but totally dispense with Trent when it comes to its decrees on the formation of priests. Trent was very clear: no more apprenticing to a bishop, informal training. That was a disaster, especially when so many good clerics died in the Black Death and there was a severe priest shortage. The temptation is too great to ordain men early, etc.