Maybe the reason people are most comfortable with "heteronormativity" is that it is far less Byzantine than homosexuality/transgenderism/etc.
Update: On a more careful reading of the post, I suddenly realize what specifically it reminds me of that makes it seem so silly. This debate is essentially like those of science fiction fans who prattle on endlessly about how the Klingons are different that tne Romulans, or who discuss who would win if, for example, Galactus and Unicron had a battle. Not that such topics are not interesting, but there is something bizarre about the idea that they ought to have a whole lot of political/social import.
That is all.