In truth, there are lots of men among the Erotica writers. Twitter is full of "coming outs" of men writing lesbian erotica, hotwife, cheating, and whatever kinds you may thing about.

And they sell, so they'll be likely be hit by this, too (I know at least 3 regularly published on MyErotica with genderless nicknames).

To me, it's simple hypocrisy. Especially in America, everything revolving around sex is always seen as taboo, whoever is the seller.