Catholics couldn't be expected to know how to interpret Scripture for two reasons.
One is that they've never been taught how to interpret Scripture. As you correctly said, it's interpreted for them and spoon fed them.
The other reason is lack of practice doing so. You can't practice what you weren't taught.
A Catholic telling a Protestant how to interpret Scripture or passing judgment on a Protestant's interpretation of Scripture, would be like me telling Michael Phelps how to swim.
How can a person interpret Scripture without the Holy Spirit to guide them? Without the Holy Spirit, it’s nothing more than seeming contradictions and confusion. Perfectly designed for “teachers”, having itching ears...wanting to be told what to believe, say, pray, and do for God’s approval.