I guess I don't even care if a person want to say in public that Vatican II was a heresy (I see you Ross Douthat!), you cross the line as soon as you project that you are judging or invalidating someone else's choice for themselves, whether you do it for religious grounds or atheistic philosophy grounds. You can tie this right to what is so wrong about Alito on the SCOTUS (and Scalia before him, whose son was an RC priest IIRC). He seems to think his view of proper RC/Christian history and culture should have some currency to decide what other people do with their lives. If he wants to live that life, fine, but leave it at the courtroom door or find a new line of work for the sake of the rest of us.