Clearly our beloved Willow cannot be blamed for going dark. She was but a young high school student, clearly on her way to Harvard or Yale, before Buffy and Giles corrupted her.
Corrupted... hm, thats' a way too strong a word in this for me. And even if you're a young high school student there is such a thing as personal responsibility. Not to mention lessons to be learned, that you need to learn on your own through your own mistakes...
As for corrupted, lining up to help with what Willow seemed to consider a 'higher mission' of saving the world on a weekly basis and helping her friend not die. I'm not sure I'd say that's being corrupted.
Giles, as the older, wiser, and highly educated Watcher, who seems to know everything about everything, thanks to his books, failed to realize that the highly intelligent Willow would learn magic so quickly. Why didn't he see it coming? Hadn't this happened before? Didn't the Watcher's Council or Wesley see it coming? So many wise men failed to see what was happening.
It's really easy to condemn people for missing something that seems so blatantly obvious in hind sight, but like with any abuser, Willow's problems came very gradually. It's not uncommon that parents could miss the decline into a destructive life style so to say that Giles, Wesley or the Watcher's council (based on their 'intelligence') should have seen it coming is unreasonable.
Also, not to be harsh, but it wasn't as if their eyes were on Willow. They were all there to further the cause of the Slayer and to, repeatedly, save the world from evil. If something slips through the cracks, even in their midst, I don't find it very strange at all and even less something they should be judged for. Nothing is a given, Willow could have been just fine hadn't
she made bad choice and not adhered to Giles'
repeated warnings.
Willow could have been a Nobel Prize winner. She could have cured cancer. Instead, she will forever be forced to put "Tried to Destroy World" on the job applications she submits at McDonald's, Piggly Wiggly, and Taco Bell.
And for that, I will never forgive Giles or Buffy.
Before that she was part of a more or less weekly fight to save the world, helping the side of good (she's not the first white hat corrupted by power, won't be the last, and she can come back from it.) and I'd say that that sounds just as good as "nobel prize winner" or an assistant to the cure of cancer (single handedly curing it? Nah, we're talking research and teamwork here
🙂). The only thing missing is public acclaim and a shiny plaque, both of which I'm sure Willow didn't care very much about.
But these things she
willingly gave up at the end of seasons three. And not for power. But for the cause of saving the world.