Plus, I am boggled by "writers" who don't have a massive, bone-deep need to avoid any situation that might look even slightly like plagiarism.

I agree. That's what I think is the most serious part about that. That she is this celebrated writer, but she hasn't actually acknowledged her plagerizing as plagerism (that I know of; I skimmed the history). And that's hugely disappointing - a popular writer treating plagerism as okay, basically, tolerating it, giving the impression to readers and other writers that such behavior leads to book deals.