Gosh, is it OK if I respond? Gee, I hope so.
Maybe you're just sensitive to the word "whore," but I see no real difference between "heretic" and "whore" in this context. In fact, I think "heretic" may be worse. Calling someone's religion a heresy is extremely harsh, don't you think?
Heresy is a verfiable accusation. It's a word that has an actual religious or theological connotation. "Whoring" is being employed as imagery of societal pondscum (as it were) to personify our holy mother Church. Given the context of the "Whore of Babylon", Topcat is calling us in league with Satan. If Topcat needs a Thesaurus, there are plenty of online resources. Using the word "whore" is intellectually lazy and designed to shock, not make efficacious.