The time that the Catholic church has ruled the world is very long and so it has established its roots very deep. Around the world where Catholicism has planted its doctrines, many believers say that if you were born as a Catholic then you should also die as a Catholic. They have that very firm faith in the church even if they do not find the peace they are looking for. They choose the traditions and doctrines they have been practicing that could not give them spiritual life.
You can see the present life of the believers who have grown up to only follow what the church teaches but without truly understanding the content of the bible. The church teaches their own doctrines and explains to the members the lies that they use to cover up their practices that are not in the Bible. The keeping of Sabbath alone is not practiced by them even if they already acknowledge that it is the day you can find in the bible that is established by Jesus.
What they want to do is the custom they had been practicing from the time they had separated themselves and make the church their own church and not the one established by Jesus that follow His commandments. They made changes to the word of God so that they can cover up their deeds and the believers keep a blind eye to it and just follow them. The connection they have established is hard to break but if one wants salvation, it must be overcome.