I have a theory that the intellectually lazy are drawn to catholicism for it's explanatory power. When encountered by a challenging argument straight from the Bible, if you have a doctrine of apostolic succession that involves exclusive teaching power you can just wave your hand away with some authority that said otherwise.
Your theological arguments then just become rote regurgitation of the same tired quips
>Peter had the keys to the kingdom
>Mary was born sinless (pbuh)
>Extra Ecclesiam nulla salus
>hocus pocus
Note that I am NOT saying there are no good catholic apologists or good historical theologians in the rcc. I'm saying that people who feel the need to be part of such a group seem to be drawn to it.