Dishonest and idiotic strawman.  Theologians can be wrong about something without having been "incompetent dimwits".

St. Peter Canisius, a theologian who attended and spoke at the Council of Trent, published a Catechism afterwards that received broad approbation interpreted Trent as ruling out salvation for catechumens.

Here's where Bellarmine, Ligouri, etc were wrong, and it's not due to incompetence or maliciousness, but inexperience.  Not theological inexperience, nor lack of sanctity, nor lack of IQ...what they were missing is chaos, spiritual warfare, and human degeneracy.  They were missing the "real life" application of this BOD concept.

The early Church Fathers lived in times similar to ours.  Persecutions, heresies everywhere, antipopes, truth under constant attack.  +Bellarmine, +Aquinas, +Alphonsus lived in calmer times, when the Church was not ravaged by spiritual war, when people did NOT question the most basic of truths.  Sure, there were heresies of those days, but not to the extent of the early Church nor our times.

So, when +Bellarmine, etc were thinking of BOD, they did not (could not) envision a time when 95% of churchmen believed that Jєωs could be saved, as Jєωs.  Or that "all religions are pleasing to God".  In other words, their error was in not forseeing/projecting out the conclusions of BOD, which have led to the heresies of universal salvation/implicit faith.  In their day, they were simply thinking of the "poor native indians".  They were not thinking of the horrors of V2, the coming one-world church and the false ecuмenism of our day.

These are the same people who "piously believed" that God would not allow the pope to fall into heresy.  Well, they were totally wrong.  God has allowed it.  And God has allowed Trent's "justification by desire" to turn into a replacement for baptism, which applies to anyone who "loves God sincerely".  They were naive.  They couldn't foresee the future.  It's not that they were dumb or malicious.  They were just unprepared for the 20th century and V2.  How could anyone predict this?  A crisis unparalleled in all of Church history.

Dishonest and idiotic strawman.  Theologians can be wrong about something without having been "incompetent dimwits".

St. Peter Canisius, a theologian who attended and spoke at the Council of Trent, published a Catechism afterwards that received broad approbation interpreted Trent as ruling out salvation for catechumens.

5. Born again of Water.] As no man can enter into this world nor have his life and being in the same, except he be born of his carnal parents: no more can a man enter into the life and state of grace which is in Christ, or attain to life everlasting, unless he be born and baptized of water and the Holy Ghost. Whereby we see first, this Sacrament to be called our regeneration or second birth, in respect of our natural and carnal which was before. Secondly, that this sacrament consisteth of an external element of water, and internal virtue of the Holy Spirit: Wherein it excelleth John's baptism, which had the external element, but not the spiritual grace. Thirdly, that no man can enter into the Kingdom of God, nor into the fellowship of Holy Church, without it.


Whereby the *Pelagians, and Calvinists be condemned, that promise life everlasting to young children that die without baptism, and all other that think only their faith to serve, or the external element of water superfluous or not necessary: our Saviour's words being plain and general. Though in this case, God which hath not bound his grace, in respect of his own freedom, to any Sacrament, may and doth accept them as baptized, which either are martyred before they could be baptized, or else depart this life with vow and desire to have that Sacrament, but by some remediless necessity could not obtain it. Lastly, it is proved that this Sacrament giveth grace ex opere operator, that is, of the work itself (which all Protestants deny) because it so breedeth our spiritual life in God, as our carnal birth giveth the life of the world.

Though in this case, God which hath not bound his grace, in respect of his own freedom, to any Sacrament, may and doth accept them as baptized, which either are martyred before they could be baptized, or else depart this life with vow and desire to have that Sacrament, but by some remediless necessity could not obtain it. Lastly, it is proved that this Sacrament giveth grace ex opere operator, that is, of the work itself (which all Protestants deny) because it so breedeth our spiritual life in God, as our carnal birth giveth the life of the world.

If God "accepts them as baptized," and they are saved, then baptism retains its necessity.

Thank you for your kind words.

If by "strawman" you mean incompetency isn't the only explanation, I agree.

I'll quote the Rheims annotation of  John 3:5 again:


If God "accepts them as baptized," and they are saved, then baptism retains its necessity.

It is evident, both from Bellarmine and Billuart, that no one can be saved unless he belongs to the visible communion of the Church, either actually or virtually, and also that the salvation of catechumens can be asserted only because they do so belong ; that is, because they are in the vestibule, for the purpose of entering,  have already entered in their will and proximate disposition. St. Thomas teaches with regard to these, in case they have faith working by love, that all they lack is the reception of the visible sacrament in re ; but if they are prevented by death from receiving it in re before the Church is ready to administer it, that God supplies the defect, accepts the will for the deed, and reputes them to be baptized. If the defect is supplied, and God reputes them to be baptized, they are so in effect, have in effect received the visible sacrament, are truly members of the external communion of the Church, and therefore are saved in it, not out of it. *(footnote: * Summa 3, Q. G8, a. 2. corp. ad 2. et ad 3.)


Bellarmine, Billuart, Perrone, &c, in speaking of persons as belonging to the soul and not to the body, mean, it is evident, not persons who in no sense belong to the body, but simply those who, though they in effect belong to it, do not belong to it in the full and strict sense of the word, because they have not received the visible sacrament in re. All they teach is simply that persons may be saved who have not received the visible sacrament in re ; but they by no means teach that persons can be saved without having received the visible sacrament at all. There is no difference between their view and ours, for we have never contended for any thing more than this ; only we think, that, in these times especially, when the tendency is to depreciate the external, it is more proper to speak of them as belonging in effect to the body, as they certainly do, than it is to speak of them simply as belonging to the soul; for the fact the most important to be insisted on is, not that it is possible to be saved without receiving the visible sacrament in re, but that it is impossible to be saved without receiving the visible sacrament at least in voto et proximo, disposition.

http://orestesbrownson.org/210.html

Can you cite a text where St. Peter Canisius "ruled out" salvation for catechumens who died before baptism, which is what those who read the Catechism in favor of BOD argue?

Thus, water baptism is necessary for salvation.  BOD just provides grace/justification.