Given that there are many atheists and Marxists and islamists wandering about today, all of whom have infiltrated all nations of the West, many with the express intention of infiltrating Western institutions and destroying them, please let me understand why you are laying this at the feet of "Protestantism", which is one of the least organized religious groups anywhere -- by design. No central earthly authority, no popes nor kings, no president, no magisterium, no single point of ultimate worship or system of basilicas or the like -- please explain where you are coming from.
We do need to look at the empirical facts. If a bunch of evangelicals of different stripes really ARE throwing this kind of old junk in the face of the modern Roman Catholic church, then it is reasonable to ask why.
However, I think the premise will fail. It is more likely a small number of malcontents who might not even agree with half the people in their own congregations.
"atheists and Marxists and islamists" rarely have the institutions peculiar to the Catholic Church, such as Catholic monasteries, schools and charities as a target. None of them would have the mean spirit to attack of all people the nuns. Needless to say, I don't see an atheist or muslim posting here and pinging me. The Irish burial well scandal has every hallmark of Protestant scandal mongering. Besides I don't really care about what atheists and Marxists and islamists think, whereas Protestant profess an interest in Christianity, the Holy Scripture and the life of the Chruch, and these are things I know something about.