Everyone is missing the point:
The question to ask is "HOW did the dialogue Mass succeed in spreading through Belgium, France, Germany and the low countries way back in the 19-teens?"
In the SSPX seminary, we were taught that the modernist liturgical reformers came from these countries, and networked to proliferate their anti-liturgical ideas via liberal bishops, seeking "experimental" permissions which would later become the norm.
There was no such thing as the dialogue Mass before this time anywhere in the universal Church (unless through condemned archaeologism, you want to skip 1500 years of liturgical development, and arrive back in the primitive Church).
It does not matter what this or that custom is in this or that other country:
The dialogue is a modernist innovation (I should say "dialogue Masses," since there are several from which a priest can choose from, just like the Novus Ordo), and it gained predominance in Europe (then elsewhere) via the machinations and connivance of modernist "reformers."
Can anything born from treachery and deception acquire "legitimacy?"
I could say much more on the subject, but keep this in mind: In those places which now make use of it as the norm, it did not exist prior to 1920.
Invariably, someone will say, "But Archbishop Lefebvre did not have any problem with it, so why should I?"
To which I respond, "By the time Archbishop Lefebvre was ordained (1929), he had already witnessed the spectacle of Pius XI saying the dialogue Mass on several occasions, and none in the Church at that time (except for the modernist reformers, of course) knew where they would take the false liturgical principles contained in the dialogue Mass(es). He is not to be blamed.
What I did find striking, however, is how we could be taught in Liturgy I class all about this illicit history, and then on Saturday be forced to babble a dialogue Mass.
Matthew (who was in my same class in the seminary) can vouch that one time I asked Fr. Iscara (who taught Liturgy I) during class:
"What do you say to those who observe that all these same anti-liturgical principles of the dialogue Mass are contained in the Novus Ordo, and that the former was used as a bridge to prepare the terrain for the latter?"
His response?
"You need to go talk to the bishop."
Obviously, there was a French/Swiss mandate to import these illicit French customs into the seminaries (and the schools throughout the world as well), regardless of their origin, and the incongruity and awkwardness of comparing/contrasting what we were being taught in the classroom, with what was transpiring in the chapel on Saturdays, was uncomfortable to say the least!
Meanwhile, a stealthy "don't ask/don't tell" approach to exporting the dialogue Mass (even into the more traditional English-speaking countries) is taking place:
I was in an SSPX chapel for 15 years before I knew they were saying the dialogue Mass at the local SSPX academy here (which was one of the main reasons I decided against enrolling my children there this year):
A friend writes me that in his New Zealand SSPX school, the dialogue Mass was snuck in without informing any of the parents, and I should be very surprised if he was merely uninformed (or worse yet, a liar).
The methods of spreading it are the same today as they were 100 years ago in the time of Dom Lambert Beauduin!
Minds are being prepared to accept the dialogue Mass as "normal."
And if you don't fight it, it WILL become the new "normal."
I'm not going to get into any forum debates about the matter, but for any who are interested in a more thorough explanation of the illicit origin, and uncatholic liturgical principles contained within the dialogue Masses, check in on Sodalitium Pianum, where I will be writing on the matter soon.
Meanwhile, you can start reading this series: http://www.traditioninaction.org/HotTopics/f073_Dialogue_1.htm
Semper Idem,
Sean Johnson