It’s the wider Catholic world where the teaching has been horrid that don’t know this stuff. And I don’t know anyone who has fallen away due to any of these points. It’s mostly been temporal, humanistic things and generally involves sex.
You are so right. Imagine my surprise when my daughter, who had had 12 years of Catholic school education, told me she thought sex before marriage was a venial sin.
She cried a bucket of tears when she finally heard the truth. And I cried a bucket of tears that I had passed on the faith so poorly. My assumption that they had been drilling that into the kids was incorrect. They certainly did when I was in Catholic high school!