There is only one brand with 22 different flavors.
"The Catholic Church is the work of Divine Providence, achieved through the prophecies of the prophets, through the Incarnation and the teaching of Christ, through the journeys of the Apostles, through the suffering, the crosses, the blood and the death of the martyrs, through the admirable lives of the saints. When, then, we see so much help on God's part, so much progress and so much fruit, shall we hesitate to bury ourselves in the bosom of that Church? For starting from the Apostolic Chair down through successions of bishops, even unto the open confession of all mankind, it has possessed the crown of teaching authority." - St. Augustine of Hippo ("The Advantage of Believing" 4th century A.D.)
IMHO (and not being Catholic, someone correct me) Catholics by and large believe that the Catholic church is the only legitimate denomination/church. So, of course they aren’t going to be open to switching denominations when their basic belief is that there is only one denomination to begin with.
Protestants believe that any group of believers can get together and form a legitimate denomination/church (”For where two or three have gathered together in My name, I am there in their midst.”)
I don’t what to start a debate about what is/isn’t a legitimate church, just to point out that the suvey results are predictable based upon the fact that Catholics and Protestants generally have differing opinions on the subject.