I was just thinking about an analogy that might help: suppose I’m the pastor of a Roman Catholic parish, and every Tuesday I lead a discussion group about the differences and similarities between Catholicism and various Protestant denominations; and suppose further that every Wednesday I teach a class about Catholicism for Protestants who are thinking about converting or who just want to learn about Catholicism.
Needless to say, I want to encourage people to join both groups, right? But let’s say a Protestant comes up to me and tells me he wants to join one of the groups, but hasn’t decided which one. What would I say to him? Unless I’m unusually ecumenical-minded, I’m going to prefer that he join the class on -]Tuesday/-] Wednesday, right?
I think it’s basically the same thing here: Catholics on CAF (posters and mods alike) do want Protestants here, but they’d prefer participation on sub-forums like “Apologetics” and “Eastern Catholicism”, i.e. sub-forums where the focus is on learning about Catholicism, rather than the “Non-Catholic Religions” forum where the focus is on “equal time” and what-not.
Hence, lumping various “Non-Catholic religions” together under the “Non-Catholic Religions” forum may serve a useful function, insofar as it nudges Orthodox and Protestant posters in the direction of those other forums.
(Needless to say, this is really nothing like Protestant forums that use headlines like “False Religions and Cults: Catholics, Wiccans, Lutherans, Satanists, Mormons”. Although I think that particular quote came from the phony website, but you get what I mean.)