I have met several people who remain RC but do not attend any church and are stunted in their christian walk because of it. The reasons they have given are varied and include birth control, pedophilia, liberal practices, and so on. They refuse to attend anywhere else because they are Catholic and believe there is only one church. They count on their baptism and the prayers of their families to save them.
I hope this was not the case with your Dad, xzins.