The discussion covers a lot of additional ground, including the division between so-called literary and media SF fans (coincidentally, also the current topic of discussion by Mr Happy).
Also a discussion of 'why Fundamentalists think RPGs are evil'. I don't personally play RPGs, or have much interest in them, no offence to enthusiasts. However the following post from Avram interested me a great deal.
Some people just have very low tolerance for complexity. You've probably met people who know how to sort of do one or two things with a computer, by following step-by-step instructions, but if something changes so that their instructions no longer work, they're hosed, because they can't handle the complexity of actually learning how the computer works. Or you've had the experience of explaining something complicated to someone, and seeing their eyes glaze over as you overwhelm their complexity buffer, and they say something like "Look, just tell me, is it this or that?"
That's what Fundamentalism is to many people. (Not for all -- high-complexity types can also imprint on a literalist interpretation of a religious text, but that's a different matter.) The real world is just too complicated for them, and they need someone to give them a list of simple signs they can use to tell if something is Good or Evil. Fantasy RPGs, what with all those demons and spells and stuff, trigger the Fundies' evil-detection heuristics, and you can't explain to them why they're wrong because their complexity buffers won't hold the explanation.
And there's more to it than that, of course. Role-playing, like acting, is a way of exercising your complexity buffer (because you need to get someone else's way of thinking into your head as well as your own). For a low-complexity person, having your kids turn out high-complexity can be a frightening prospect. It's like they're turning into aliens or gay atheist communists or something.
Perhaps for some people complexity is evil. I am reminded of the anthropological conception of 'pollution' as the mixing of categories. The mixing or confusion of distinct conceptual categories is associated with anxiety and hostility. We can see this most clearly in other societies which divide the world along diferent concenptual lines than ourselves. I think the fear of complexity (incl. fear of homosexuality, feminism, fiction etc.) is fundamentally fear of pollution of categories.