It's probably a clumsy sentence. Let's try it this way:
I don't hate Catholics, but I'm deeply contemptuous of the mere men in the Catholic church that declare policy and doctrine, and regard them as running a con job on innocent folks.
Well, I'm giving the folks the benefit of the doubt by assuming they aren't complicit with the con and just buy the line wholesale.
Well, "mere men" have always declared policy and doctrine, since the days of the apostles. We trust that they are guided by the Holy Spirit, but I can understand how one can dismiss that notion when seen through his merely human perspective.