Exactly What It Says on the Tin

For many years I've been a fan of a certain genre of, um, adult blogs featuring captioned photographs of women, where the captions tell fantasy stories about how the women used to be men before some magical or technological intervention. The titles of the blogs often contain the word transgender (or the abbreviation TG). I remember dimly thinking—never in so many words—Gee, I imagine actual transgender people would be pretty offended if they knew that the word used to refer to them was being used to describe this kind of material!

... why

What kind of pornography did I think pre-trans women used?

Why didn't anyone just tell me?!