The "faith" of the people has changed since the introduction of the Novus Ordo Missae.  Lex credendi, lex orandi indeed.
Here are some of the things that New Order "Catholics" believe today, which we see in their very own posts daily on this site alone:
-A belief that the murder of unborn children is acceptable 
- gay "marriage" is acceptable 
-gay sexual relationships are not intrinsically sinful
- situational ethics are fine
- divorced and "re-married people living in a state of sin aren't actually sinning and should be allowed to receive the Novus Ordo cookie
- only 22% of "Catholics" believe in the Real Presence 
- sins against the 7th commandment are fine if the government sanctions such activity
- De fide sacramental theology is to be tossed aside in favor of "equality"
- all are saved, including heretics, pagans, Jews, Muslims, and even atheists, in contravention to Catholic dogma

To allow the traditional Mass is to undo the political machinations & heresy of the New Order.