You know, even if you ignore the racism, the fic is a steaming pile of poorly done boredom. Even if you can't see racism for some reason, it's just terrible. It's like a fic consisting of one boring joke, done 50 times.

So how come so many people like it?

It seems racism itself is the reason. That's the part people like about it. Which explains the reactions from her fans to "this is racist" really well.

Racism is bad, but it's what they like about the fic, therefore it's good, and not bad, and thus not racism. QED.