Rather ironic that they celebrate diversity among themselves and yet still claim to be in communion with each other, and yet when those outside Catholicism are diverse, RC's are condemning it as being an indication the error of *sola Scriptura* and it's proof that Protestantism is not the OTC.
To be fair, despite our differences in dealing with/explaining the post-Vatican II crisis in the Church, traditional Catholics hold to the same pre-Vatican II Faith. Of course there are some who call themselves traditional Catholics, but they merely “prefer” the Latin Mass over the Novus Ordo service. For them, the only issue is the liturgy and they see nothing wrong with Vatican II other than its so-called “ambiguities”.
The "married" lesbian music directors with the clenched fists at St. Michael's in Ireland and their infernal excuse for a pastor are NOT Catholic whatever the circumstances of their baptisms, if any. Nor are Pelosi, Rosa DeLauro, Patty Murray, John Kerry, Tim Kaine, Susan Collins, and a host of other once Catholic political apostates. They have excommunicated themselves.
It goes without saying that there is "diversity" among the Reformed. Protestantism cannot be the One True Church because Protestantism, as such, is not one. Protestant churches contain much truth and many truths which differ in some respects from church to church. In and of itself, such differences prove nothing other than that "Protestantism" has many principled variations and is not "one."
Sola Scriptura assumes, without proof, common agreement on what Scripture truly teaches. On their own, neither Catholics by their own talents, nor Reformed Christians by theirs agree completely on the entire meaning of Scripture.