Dittos to what the others have said, with the added thought that there are so many "cafeteria Catholics" who pick-and-choose which doctrines they believe and which moral teachings they accept (e.g., contraception), that a Catholic may call himself a Papist as shorthand for saying "I accept the teachings of the Catholic Church on all matters of faith and morals."
In that sense it becomes more "common usage" for faithful Catholics.
On the traditional wing, it also becomes shorthand to distinguish traditionalists who accept Vatican II and the popes from John XXIII through Francis from sedevacantist traditionalists who reject Vatican II.
Dumb question, which is the papist, the traditionalist supporting VatII?