Quite a number of things feminists find problematic in fiction are so not because of anything intrinsic in them (surely stories don't really have any intrinsic meaning, really; they always only mean something to people who have interpreted them somehow), but because in the context of broader culture those things have Unfortunate Implications. Now, simply avoiding doing anything that has Unfortunate Implications severely restricts what can be said about women, which in turn has Unfortunate Implications of its own. So, short of just fixing all of society so the context isn't so troublesome any more, there are always going to be hard choices, and reasonable people are going to disagree about whether the right choice has been made. The present critique is pointing out, correctly, that Hermione's fate has Unfortunate Implications. Perhaps there was a better way to tell the story, but one can point out the UIs without knowing such a better way, and even if one doubts that it really exists; drawing attention to UIs may improve understanding and contribute to other projects even if there is no fixable deficiency in the present target.