Theologically, I understand your point.
My question has more to do with COUNTING the number of adherents.
It looks like when we count adherents of certain denominations (Catholics or Protestant), we count them based on Baptisms even when many of those who were baptized ( at birth or as adults ) have turned against their faith and openly profess some other beliefs (or non-belief).
Those are the ones the media counts as catholics when they vote for the likes of Zero.
I seriously doubt that this fine upstanding individual is a registered member of any parish, so I seriously doubt that the Church counts him in any sort of census of members. For the first few years of my adult life, I probably wasn't 'counted' either ... even though I was a regular participant in the life of the Church.
I have no idea at all as to what this fine upstanding individual would tell a public opinion pollster, if asked his religious affiliation. If this FUI responded 'Catholic', the pollster would record such, regardless of the FUI's actual beliefs and practices. If the FUI claimed to worship the Great Purple Horned Toad ...