I think many people who are insecure in their tastes blackbox whole categories. I've got colleagues who ask for my fiction for a literary magazine; I've got colleagues who say that they just can't read science fiction (and they're not being snarky and dismissive and they have tried to read s.f.). I think there's a strong tendency in s.f. to write things that if taken to RL would lead to fascism -- the Emperor of Everything novels -- but there are good and badly done examples of those. People who consider those sorts of novels to be problematic (and the objection is primarily based on non-esthetic reasons) won't like that sort of s.f., and probably won't understand novels that deliberately play with that s.f. convention anymore than someone who wasn't ever going to read Jack Chick tracts would appreciate parodies of those.