Trouble is, if they understand it correctly, they will not join the Catholic church.
What an odd comment. Apparently, you have no understanding of the history of the Bible.
Ah yes...the church was qualified to decide which books are to be included...but not qualified to interpret it...got it
This is a tautological observation; you can simply say that anyone who reads the Bible and becomes a Catholic didn't "understand it correctly"*. Who gets to decide what is, and is not, a "correct understanding"? You? What are your credentials?
*Despite the fact that I can name several people who read their way into the Church who were previously thought to understand the Bible correctly when they were chosen to pastor Protestant churches.