And a dishonest Protestant doesn't agree with you?
Agreement with or disagreement with, the Catholic church on opinions is not a matter of honesty or integrity.
And while I do think that most Catholics BELIEVE that the Church derives its teachings from Scripture because that's what the church tells them and they've been raised believing it since before they could walk or talk.
However, I would not be honest if I agree with your statement because I don't believe it. So if I state outright what I believe which is disagreeing with you, then I am being honest. If I agreed with your statement, then I would be dishonest because I'd be lying about what I believe.
It is one thing to say that Catholics got it wrong when interpreting Scripture but another to say that we have not made the attempt. Do you truly believe that Catholics have not studied the Scriptures to understand what they teach? The use of Scripture by Catholics from the early Church to the present would belie such a statement.