Calling a zealot a zealot does not mean that one is incapable of discussing the underlying topic. We must not let the desire to converse intelligently hamstring our ability to call out obviously corrupt patterns of thought for what they are.
Anyway my above reply was hardly the appropriate venue to engage in a genuine manner on that topic. The parent was blatantly derailing things by inserting his pet political issue. That sort of behavior undermines the community and so (IMO) should not be indulged.
I agree, and I also agree that zealots who cast anyone who disagrees with them as being literally insane should also not be indulged.