My mother was one of those Catholics. She ended up being able to perform any task with either her right or her left hand equally well.
My grandmother was one. She ended up thinking society was screwed up and vowing to never mess with her kids that way. Which let my mom be left-handed, and then me. Give that it’s totally genetic and nothing the kid can decide (sure you can train your off hand up, but that doesn’t change how you’re wired) it was a pretty screwed up mentality, one might even call it sinister.