Long time geek, fangirl, mother, and reader. I've got a lot to say, you might not like it all, but it will be honest and hopefully helpful.
A few reasons why ignoring Anime fandom in a book about fan fiction is it miss represents the true history, and multicultural roots of media based fanoms.
Case in point: Kink Memes got their start in Anime fandom (Bleach fandom in 2007 to be specific). Also Twilight fandom regularly used the Anime fan fic term "lemons" to describe stories with explicit sex.
Not that Asian culture only gets noticed when it's exploited by Westerns...
I'll take white washing fan culture for $200, Alex.