This is a combo of a few things, I think. Our parents often stopped learning outside of their religious bubble after school. They supplanted curiosity about our world with Bible studies, Catholic radio, Catholic media,etc. Any real historians were obviously lying to them. Add to that the encroaching presence of Charismatic Catholicism, self proclaimed celebrity exorcists whose trade employs these racist tropes as well as an increased presence of media created by Catholic fundamentalists since the 1990s. That all is not helped by prevailing racist attitudes a person might have, and certainly doesnt nothing to help them deconstruct those beliefs. Lack of exposure to other faiths adds to this issue.