I'll expand on this later.

It's a loophole. If Rome made the Mass exclusively in the vernacular and forbid Latin it would be an unjust law and it would be anathema. they did not do forbid it in theory, but they pretty much did it in practice by making vernacular 99.99% of all Masses. Plus you cannot change the substance of the Missal by Quo Primum which is what the Reformers did. The Novus Ordo Missae was never promulgated officially nor made binding to the Church. Hence, the bull Quo Primum is the one which is still in use, thus binding all Priests of the Roman Latin rite to the Missal of Saint Pius V, under pain of severe penalties.

So since this is the case, and Quo Primum is still binding, the Norvus Ordo Missae is illicit. Though it is still valid, if the priest and sacraments are valid.

It’s a schismatic rite, as per Quo Primum Tempore and the Council of Trent. Valid and illicit if said in Latin, invalid if in the vernacular. See https://www.youtube.com/watch?v=yXqneqIafVI.

The Pope has the right to promulgate a new Missal, but Paul VI did not do that. The original Latin text of Missale Romanum of 1969, does not say that it promulgates a new law, nor does it say that the new Missal has the force of law. The English translators mistranslated the Latin and makes it say that the new Missal has the force of law. Compare this correct translation, to the English translation, found here:
http://www.vatican.va/content/paul-vi/la/apost_constitutions/documents/hf_p-vi_apc_19690403_missale-romanum.html
https://www.papalencyclicals.net/paul06/p6missal.htm

And if it were promulgated, the Holy Spirit would not have been protecting the Church. If you want to promulgate a rite (which you can’t, you’d cease to be Pope), you’d have to bind the entire Church in a document like Quo Primum. All Paul VI did was say he’d like people to use it, literally. He’d like people to use it. Lol. Such authoritative papal language.

Fr. Hesse said that Popes are not bound to follow their predecessors in matters of discipline. However, in matters of faith and morals, the Pope is bound to follow his predecessors. Is the Roman Missal a disciplinary matter, or a matter of faith? Well, It’s a matter of discipline just as much as the canon of Sacred Scriptures. Whomsoever of the pastors of the Church includes the Pope, and the council of Trent is extremely straightforward.

Usually, when the current Pope wishes to say something new, he writes his own document and throws away the previous one.

With the Missal, however, when a new Pope said something, he would add his document AFTER Quo Primum, never throwing it away and always respecting it.

SO How can people say then that either Holy Mass is simply a disciplinary matter, or that Quo Primum is merely legal and not at least in some extent infallible? It is ridiculous.

Quo Primum canonizes the Missal of the Roman Rite as the mass of the Latin Roman Rite. It is an infallible document binding to all future Popes. It rightly suppresses and condemns any rite without at least 200 years of tradition. Such is the case with the schismatic NO. See https://www.youtube.com/watch?v=FABY6aIJw6A where Fr. Hesse explains this in-depth.

“Trent’s decree and Quo Primum are not “matters of ecclesiastical law” but of Divine Positive Law based on revelation. Therefore, Paul VI had no right to change the liturgy.”
- See Canon 13, Session 7 and Canon 9, Session 22 of the Council of Trent.

Quo Primum: https://www.papalencyclicals.net/pius05/p5quopri.htm

Council of Trent:
http://www.saintsbooks.net/books/The%20Roman%20Catechism.pdf

Also, for you NOites. Yes, the Norvus Ordo Missae is valid itself, but it is illegal/illicit. Which I have proven.

Courtesy to twitter.com/knight_atlantic for providing most of the information I've gathered here.

I have to note too, "reformable" really isn't the best word to use when discussing QP

Fiat voluntas Dei; God’s will be done

“Some aspects of God’s will are revealed to us by the eternal truth of Nature.

Other matters depend on God’s free choice. To know God’s will in those matters, he has to reveal them to us. We know Christ wants people to be baptized, because he told us.

Most of the time, our own decision-making process involves discernment using the virtue of prudence and the gift of counsel, not explicit divine revelation. God doesn’t tell us whether to eat ham or turkey for lunch.

To seek undue certainty about the future or the hidden things of God, things he hasn’t revealed, is divination. To make assertions about what is or isn’t God’s will in respect to contingent events is dangerous—appointing oneself as God’s prophet or mouthpiece.

This is an affront to God’s sovereignty, as if God cannot act or refrain from acting as he chooses. It also belies a lack of trust, as if we don’t expect God to do anything and instead invoke him like some kind of talisman.

The cases where we can speak for God is the cases he has given us, written in the book of Nature or the book of revealed truth, entrusted to the Church and to those whom Christ appointed to teach on his behalf.”

~Fr. Dylan Schrader

A man brought in a Midianite prostitute Into his tent, Phinehas son of Eleazar and grandson of Aaron the priest saw this, he grabbed a spear and ran into his tent, he thrusted his spear through the man and out through the prostitute.
Tolerance is not a Christian virtue, tolerating grave sin in society is a form of sin in itself. Obey God.

Another Question relating to QP is:

Since a Pope cannot bind another pope in matters of discipline, but then why did the Popes after St. Pus V bother to keep Quo Primum in the Roman Missal and bother explaining why they made some extremely minor modifications that didn’t change the offertory or the substance of the Missal itself?

Pope St. Pius X, pray for us.

Leo of Rome, Letter to Paschasinus:

'And they think they can deceive our attentiveness when they say they believe the one nature of the Word to be incarnate.'

St Cyril of Alexandria, 2nd Letter to Succensus:

Corporatism is the Catholic solution to the moral evils and practical abuses of both free-market liberalism and totalitarian socialism.

“Even in its outward and social sense, legitimate war, which is waged against the disturbers of order and aimed at reimposing order upon them, is essentially a function of ‘justice,’ or in other words a balancing function, whatever the secondary and transient appearance may suggest; but this is only the ‘lesser holy war,’ which is a mirror image of the ‘greater holy war’ ... The ‘greater holy war’ is man’s struggle against the enemies he carries within himself, that is, against the elements in him that are opposed to order and unity.” -René Guénon
***
Though it appears to have its basis in disorder, legitimate war not only produces rectification, in accordance with just war doctrine, but also opens the door to higher possibilities for those capable of receiving them. Therefore, the supremacy of the spiritual over the temporal is affirmed, and the emphasis on material loss or gain is all but eliminated.

Today we remember St. Jose Sanchez del Rio.

As a child, he was kidnapped and brutally tortured by pro Masonic forces loyal to the government of Mexico. They cut the soles of his feet and made him walk for miles, expecting him to renounce his faith.

Instead, he defied them and exclaimed 'Viva Cristo Rey!'

Long live Christ the King.

Jose Luis Sanchez del Rio, pray for us that we may follow in your footsteps.

Watch For the Greater Glory

Jose Sánchez Del Río! ¡Presente!
¡Viva Cristo Rey! https://youtu.be/AaICvxwpw8w