This argument makes no logical sense. Roman Catholics trace the origin of our church back to the martyrs in Rome like St. Peter, the first Roman Catholic Pope, and other early Christians persecuted and killed by the Roman pagans. Every Protestant sect traces itself back to the exact same people (St Peter and early persecuted/ killed Christians). It’s not like the Roman Catholic Church was founded by the Roman pagans who were killing the Christians.
Moreover, in the time of the early Roman persecution and for 1500 years thereafter, the Protestants were all members of the Roman Catholic Church themselves. So we all trace ourselves back to the same group. It’s not like the Protestants were Team Christian, with St. Peter and Paul and whoever on their team, and the Catholics were Team Roman Pagan with all the murderous Roman emperors on their team.
This statement by any Protestant is totally nonsensical and one would have to be completely uneducated about history to think it has any merit at all.