Intellectual honesty means counting the Catholic vote, it is a single church, with a single teaching, and a single culture, not a collection of churches of vast diversity such as the category “Protestant”, it does not mean giving a purity test to see if they should be excommunicated by the church and forbidden to identify as Catholics, and removed from being counted as Catholic by the Vatican, all according to some guys personal definition of purity.
It is a single Church only to the extent that its adherents are in communion with it. You can no more declare yourself a Catholic than you can declare yourself an NFL quarterback. As Socrates said: "To do is to be." If you claim that every church shopping and hopping Protestant is somehow intrinsically different than every lapsed and ex-Catholic you are going to have to substantiate that more thoroughly than simply pointing me to a website stuffed with irrelevant polling data.
Not everyone who says to me, Lord, Lord, will enter the kingdom of heaven, but only the one who does the will of my Father who is in heaven. - Matthew 7:21
Just ask how many Catholics there are worldwide. Catholics are certainly happy enough to count everyone who has ever been a baptized Catholic when it comes to tallying up their 1.2 billion strong.
For that matter, I'll bet I'M still on Catholic rolls. I never told them I left and nobody ever noticed I was missing and tried to contact me about it.
And it's no surprise. What with the way the priests rotated through the parish, there's no way to keep track of all the parishioners. Heck, we couldn't keep track of the priests and there were far fewer of them than us.