From what I understand, at least in regards to Shiloh Walker's position, is that she is aware that the material is problematic but doesn't recognize it as a problem (if that makes sense). It seems to me that she believes that readers can easily distinguish between right and wrong, regardless of the context or lack thereof. Mind you, this is just my interpretation.

I actually wrote a post a couple entries back about Shiver by Maggie Stiefvater, which I think may illustrate what Twilight could have been, done right.