A lot of players really wanted to see a broken Korra and Marty always wants to please his audience. Also, this book suffered a lot from the development shenanigans caused by cbob's illness. Despite the name, FET isn't really a trainer game in my opinion, in the sense where you train the girls and they enjoy it and want more. But to be fair it is called "slave route".
Except for sex role play, I never was nor will be a fan of degrading women (or anyone really), so I'm glad Mity does a good job with the love routes. It's a bummer book 1 is not at the same level the other books are though.
Btw., for a children's show, it's astonishing Korra consistently gets abused and treated badly, she's a teenager for fuck's sake. Also, I won't buy the lesbian ending they gave her, absolutely came out of the blue. If someone deserved to be in Mity's slave route, it's the writers of the show.