It amuses me that he is so militant atheist and so determined to be right about everything that he will risk ruining the remainder of his following.
That's probably it, this new venture of his has nothing to do with waking up Catholics but he just wants to hear his own voice and remind himself of how right he is in rejecting religion.
As a fellow atheist I will say it's just obnoxious behavior. Definitely call out abusive religious practices but who cares if someone believes in god, worships trees, calls themselves a warlock, or lives in a coven. Considering how stubborn he is with his own opinions, he's not exactly in a position to criticize someone else's.