Are there any high-profile Catholic athletes or other celebrities that have taken a public stand for traditional morality?
There must be, but I don't know of any.
We probably know so many Born Again Christians because they are very visible trying to share The Gospel and are so quick to offer praise and thanks to GOD for their success. RC's don't share The Gospel because for them it's all about church membership.
They've been given special mention because of their high profile in this country.
You will find Catholic athletes at ‘Catholic Athletes For Christ’
Phillip Rivers of the San Diego chargers, Lou Holtz, and Bowie Kuhn are all pretty open about their faith. Rivers was featured in the Theology of the Body DVDs I showed to my kids.
Grant Desme left the Oakland A's to become a Norbertine priest.
Those are the examples that come to mind.