It indirectly opens the door to other Catholic doctrine which conceals the true way of salvation. A Catholic who gets saved needs to leave this type of religious system as much as a Mormon who gets saved needs to leave Mormonism . There really is no difference between the two. Furthermore, Catholics who truly get saved show they recognize the serious implications of papal infallibility by exiting from this type of religious system to a local Protestant congregation that declares the true gospel as found in the Bible. To ignore such an important move can only adversely affect one who gets saved even to the point of spiritual death.
Eternity is a long time.