Anyone except Russ is invited to skip over this or have soft cushions standing by in case of keeling over with boredom.
Catholics may consider themselves Christians, but it's widely believed they're not
But Catholicism is extremely widely spread*, so therefore it follows from your statement that the belief that they _are_ Christians is quite widely spread, so you've contradicted yourself. It's the 800lb gorilla of religions. I don't think I'm being too outre to suggest that the adherents of all the other faiths in the world aren't aware of the nuances of two verses of the Bible as interpreted by yourself, and consider Catholicism as a Christian religion too, so lets add up:
1bn Catholics consider themselves Christians
6bn people in the world
So the maximum number of people who could consider Catholicism a non-Christian religion is 1bn out of 6bn in total, or 17%, under the pretty big assumption that all non-Catholic Christians regard Catholicism as non-Christian. In other words _at least_ 83% consider Catholicism a Christian faith. In other words, it's widely believe that Catholicism is a Christian faith.
Toleration - if you're tolerant, you should accept the right of Catholics to believe they are Christians, if you state baldly that they aren't, you aren't being tolerant, as this is a direct attack on a core tenet of their faith.
The vast majority of Catholics are born in to Catholicism, that is their parents decide for them. Unfortunately the Bible doesn't work this way: you must chose God for yourself, not by proxy.
The vast majority of all religious people are born into it, Catholic, Protestant, Islamic or Zoroastrian (100% in the latter case). Does that mean that they won't be saved? It's going to be rather lonely up there, y'know, if God has really hidden the secret of eternal salvation in the interpretation of the small print of the Bible.
Catholicism, incidentally, doesn't deny the need to be born again, but merely regards the requirement to be born again to be met by a conventional splashing-water-about baptism, which is a requirement of Catholicism anyway.
Jesus answered, Verily, verily, I say unto thee, Except a man be born of water and of the Spirit, he cannot enter into the kingdom of God.
Different interpretations there then, where does your interpretation of 'born again' differ from this and why?
*'The Catholic Church is the world's largest religious body' - www.adherents.com
- also the source for the other numbers.