For a professional writer you'd think she would know that a quotation (even a fictional one) requires quotation marks around it to make it clear to the reader that it's not what you are saying but somebody else. Perhaps this makes more sense:

"Refusing to accept that people who don't like sex belong in the gay category is akin to wanting segregated bathrooms in the 1950s, John," as approximately a thousand gender activists will inform you once their hands stop literally shaking.

She's mocking the people who replied to her.