To be fair, this sort of thing has been repeated by anti-Catholic polemicists since the 16th century. Or before.
The grounds for the complaint may vary, but the intensity of the hate is quite traditional.
The good (or not so good) professor is writing in quite an old tradition and has a lot of interesting company.
1. You mean, it started during the Protestant Reformation with/by de-frocked Catholic priest Father Martin Luther.
2. Yes, it is, a tradition of intense hatred. Perhaps it was started by Cain.
3. Of whom might his "interesting company" be comprised? I'm curious.