Today, his Feast Day, is the 450th anniversary of the Heavenly Birthday of Papa Ghislieri, Saint Pius V, Bishop of Rome.
Two BIG UNTRUTHS in particular are told about him, poor fellow.
Lie Number 1: he issued a radically revised version of the Roman Missal, just as S Paul VI was to do after Vatican II.
Fact: S Pius's edition of the Missal was so light a revision that it was still possible, after its promulgation, to continue to use your old Missal.
Lie Number 2: although permitting some exceptions, S Pius ordered his edition to be used by everybody.
Fact: he ORDERED all rites older than 200 years to be kept in use. (He only permitted churches with 200-year-old-or-more rites to change over to his own new edition if the Diocesan Bishop and the unanimous chapter agreed).
I hope that is clear enough. But ... so many people ... Popes ... Cardinals ... Bishops ... have such trouble with all this ... so ... here's another simple way of explaining the difference between S Pius V and Pope Francis:
(a) Pope Pius V ORDERED Rites older than 200 years to be RETAINED;
(b) Pope Francis is TRYING TO EXTERMINATE a Rite which is centuries more than 500 years old.
If people you are talking to really are so thick that they can't understand the difference when you've tried both these ways of explaining things, give up.