I preface my answer with all of this because I don't want to sound like I'm throwing anyone under the bus when I say the Quo Primum justification for rejecting the Novus Ordo and continuing to use the tridentine Mass is simply not correct. First of all it is not correct to say that a pope can make a law saying some liturgical norm must be used forever. Secondly it is not correct that St. Pius V even intended to do that anyway; when he said the tridentine missal must be used forever, he simply meant the law was permanent in that it had no expiration date. He was not saying no future pope could change what he had established. That would only be possible if it were a matter of dogmatic definition or irreformable teaching on faith or morals, which a iiturgical norm is not. Thirdly, it is not true to say that Paul VI did not promulgate the Novus Ordo, or did not tell anyone they had to use it. Paul VI promulgated the Novus Ordo missae in a similar way to how St. Pius V promulgated the tridentine Mass.

Fr. Cekada discussed all of these errors in some of his articles, one of the best of which directly addresses your questions. Because yes, you are correct that this argument is problematic and should not be used.

So, to answer the question at the beginning of the thread as to whether St. Pius V exceeded his authority, the answer is of course not. It is only people now who misunderstand the nature of what he commanded and its binding force.

Montini can say whatever.  What matters is what the law says.  Ones intent is irrelevant if the law doesn’t spell out your intent.  If Montini had wanted to get rid of Quo Primum, then he needed to be much, much clearer in his law. 

Paul VI Revokes Quo Primum

Father Laisney trots out yet another old canard: the tale that Paul VI did not abrogate (revoke) St. Pius V’s Bull Quo Primum. Advocates of this position sometimes cite a passage in the Code which states that “a more recent law given by competent authority, abrogates a former law, if it expressly orders abrogation.” Paul VI, the argument goes, did not mention Quo Primum by name, so he did not expressly abrogate it. Quo Primum, then, never lost its force, and we are all still free to celebrate the old Mass.

But proponents of this notion are engaging in wishful thinking.  Expressly, in the canon quoted above, does not just mean “by name.” A legislator may “expressly” revoke a law in another way — and this is what occurred here, when Paul VI, after he gave his volumus to the New Mass, added the following clause: “...notwithstanding, to the extent necessary, the Apostolic Constitutions and Ordinances of Our Predecessors, and other prescriptions, even those worthy of special mention and amendment.”  This clause expressly abrogates Quo Primum.

First, the Bull Quo Primum falls into the category of the most solemn type of pontifical legal Act — a Papal or Apostolic Constitution. And in the passage quoted from Paul VI’s Apostolic Constitution, he specifically revokes the “Apostolic Constitutions” of his predecessors. Second, in order to revoke a law expressly, a pope is not required to mention it by name. Express revocation also takes place, says  the canonist Cicognani, if the legislator inserts “abrogatory or derogatory  clauses, as is common in decrees, rescripts, and other pontifical acts:  notwithstanding anything to the contrary, notwithstanding in any respect anything to the contrary, though worthy of special mention.”

Paul VI, in other words, used the exact type of language required to  expressly revoke a prior law. And in so doing, Paul VI again used some  of the same phrases St. Pius V employed in Quo Primum to revoke liturgical laws of his predecessors: “Notwithstanding preceding Apostolic constitutions and ordinances… and whatever laws and customs there be to the contrary.”  Again, if this language worked in 1570, it also worked in 1969. In light  of all the foregoing, one cannot continue to promote the myth that Paul VI’s  legislation did not expressly abrogate Quo Primum.

Why would a Traditional Catholic even use this argument?  What Montini WANTED was for everyone to accept Vatican II, use the NOM, etc. ... and it's why he suspended SSPX and Archbishop Lefebvre.

Regardless, as we don't care ... the closing lines of Montini's promulgation of NOM Father Cekada pointed out was exactly how QP ended, by superceding / replacing all legislation.  That does spell out intent.  He didn't have to spell out Quo Primum by name, since there could be something else out there that he missed.  This way he doesn't have to name them all.

But this hand-wriging about legal technicalities.  It's clear that Montini and all the V2 papal claimants have insisted upon everyone using the NOM.

This reminds me of the nonsense about Ratzinger's ministerium vs. munus ... where specific terms are required to spell out your intention.  Canon Law lays down no such requirements.  He could have said, in the vernacular, "I'm doing being pope.  See ya, guys.  Find someone else." ... and that's a valid resignation.  Law only says he has to make it reasonably clear to those around him.

Same thing here, where it's very obvious that Montini intended to replace Tridentine Mass with his concoction.  Nobody doubts that.  And IF you wanted to doubt it, just check with the Holy Office.

First of all, I'm curious why you think Paul VI was able to violate Quo Primum if you think Paul VI was a valid pope?

A pope cannot bind another pope in the future with a law. This is because only a superior can bind someone with legislation, and one pope is not the superior of another -- they all have equal authority.

This is not to be confused with a doctrinal definition. When a pope teaches doctrine, it is not his own teaching that he is giving, but God's teaching. That is why one pope cannot reverse a dogmatic definition or irreformable teaching of a previous pope -- because it was really God that taught it through the pope.

This is different from legislation. If a pope makes a law, the Church has to obey it, but it is not something revealed by God. Another pope can change it.

Sure St Pius X modified the missal, but Fr. Hesse says that St Pius X explained the changes at the beginning of his missal...