A good summary of where Wrede went wrong can be found here. I have a birthday party to set up, so I'm not going to go into it in a lot of detail, but this might be a helpful exchange from a mailing list I'm on. This comes after I explain some of the problems with the whole idea of just erasing the American Indians from your novel in order to make room for a happy European-colonized America + cool megafauna. I go on to say:
MA: Personally, I love Wrede, and her writing, and I imagine I'll enjoy this book when I finally get around to reading it.
Marty: I used to! I think I'd have a very hard time reading this book at this point, and I think a lot less of her now.
MA: Oh, I don't know. I think it's a bit harsh to think less of someone because their writing happens to express a set of terrible racial ideas that almost all of us carry around with us every day. If you condemn her for making the mistake, you kind of have to condemn everyone; I find that kind of moral outrage not so easy to sustain, and not so productive either.
The question for me becomes -- once something like this is pointed out to the writer, how do they respond? Do they just defensively insist there's nothing problematic in the work? Or do they consider the issue, and perhaps, if they come to agree, acknowledge the issue publically and maybe even discuss how they might have done things differently, or how they'll do things differently in the future? That's what I'd really like to see from authors like Wrede. But I also get kind of frustrated by all the folks who expand immediate acknowledgement / contrition -- I think it sometimes takes time to really internalize how privilege works, and even longer before you can see it in yourself without reacting defensively.
Personal example: one of my earliest short stories, "Chantelle", had a bisexual female protagonist who essentially date-rapes her straight female roommate. At the time it was published, I got a couple of critiques that this was just feeding into a set of nasty stereotypes about lesbians and bisexuals. Defenisvely, I dismissed those critiques with the argument that my character was 'just one person' and 'couldn't bisexual women be just as crazy as everybody else?' It took me years before I could even see the flaw in my argument, to understand that my story may well have arisen from my own inherited homophobic prejudices (despite my being a bisexual woman myself!), and that regardless of its origin or my intent, the story functioned as part of this body of culturally-damaging work that overwhelmingly pathologized queer women.
It's embarrassing to admit now that I even wrote the story, much less that I defended it for so long. But I also think it's the sort of thing writers have to accept that they're going to fall into sometimes, because we live in a racist/sexist/homophobic/ableist/etc. society. And the key is to point out / acknowledge the mistake, and then move on, trying to do better next time around.
Speaking of which, that story is up on my website -- I really ought to make a note at the end of it addressing all of this. Add it to the to-do list. Sigh.