Fred was not evil. I highly doubt Willow would be behind Buffy on that whole thing Andrew whined about on ANGEL. Willow understands these kind of issues, what needs to be done in the process of the good fight. She also understands that it isn't quite as simple as JUST being good or evil. Remember how down she was on Faith for all those seasons. Then she turned evil, and then suddenly, next time Faith and Willow meet, Willow's as friendly as can be to her, because she gets it now. Faith was never just straight up 'I was born bad.' Her experiences shaped her into that.
Willow would understand Angel joining Wolfram & Hart, and Fred and all the others as well. I don't think she'd judge them quite so quickly as Buffy would.
Also, I should really say that I never meant that there was anything more going with Willow and Fred than what we saw. I just meant that, Willow had met Fred, she liked her, and could probably tell that she was a decent person, and then she dies, and Angel calls Giles asking him to get a hold of Willow, and Giles just blows him off. He let an innocent girl die because he didn't like who she, or they, were affiliated with. Willow liked Fred, and I imagine, probably would've angry at Giles for doing such a thing, for allowing this person that she'd met and responded to, to die, for no other reason than just out of spite.
Now, I will say that I haven't ever really been into Frillow, so that wasn't really what this thread was about. Even though I'm loving the idea of them together more and more. It's really hard not to.