When we embark on celebrating the Holy Sacrafice of the Mass it is very important to use a sacred language rather than a profane language. Latin was made sacred by being one of the languages used on the very Cross that Our Lord suffered and died on. (By definition, any language that is not "sacred" is profane. Today we have a different understanding of "profane".)
When I came home to the Catholic Church (after 38 years as an Anglican) I did so at a parish that celebrated the Traditional Latin Mass only, led by the F.S.S.P. I had spent the previous 15 years attending the parish down the road with my wife and young children, which celebrated the Novus Ordo Mass exclusively.
The BIG difference is not so much the language, but rather, the TRADITION.
The "Traditional Latin Mass" actually began in the Upper Room on Holy Thursday. The Apostles kept celebrating that Mass (although they did not have a name for it at the beginning) for a long time. The successors of the Apostles remained true to Our Lord's command to "do this in memory of Me as oft as thou shalt eat/drink it" (a paraphrase obviously).
Over the centuries this Holy Sacrifice of the Mass became codified. All I know, without doing more research, is that it took a long time and must have involved many steps.
The early Christians even had to celebrate Mass in the Roman Catacombs. (See
In The Catacombs | From Jesus To Christ - The First Christians | FRONTLINE | PBS for more info.)
Slowly the form of the Mass, that Our Lord commanded we keep, developed "organically".
Pope St. Pius V standardized the Mass by promulgating the 1570 edition of the Roman Missal. Pius V made this Missal mandatory throughout the Latin Church, except where a Mass liturgy dating from before 1370 AD was in use. This form of the Mass remained essentially unchanged for 400 years.
Then there was an abrupt change with the "manufactured Mass" (Pope Benedict XVI words) when Pope Paul VI introduce a "new order of Mass" (the Novus Ordo).
There lies the problem. God had guided His Church for centuries as to how to celebrate and slowly develop the Mass. Now we have a man-centred Mass rather than a Christo-centric Mass.
My main point in the above ramblings is that as valuable as the use of Latin is, what the vast majority of Catholics have ever known for the last 60 years would be unrecognizable to their grandparents, great grandparents, etc. It is NOT an organic development of the Mass Jesus established.
Those of us attached to the Traditional Latin Mass love it for its beauty, the sound teachings we hear (passed down via Apostolic Succession), the sacred music (Gregorian Chant). IT IS OUR HERITAGE!
To survive The Church must return to Her roots that started in the Upper Room where Jesus ordained the first bishops.
Dominus vobiscum, Reg