I want to agree, but look at all the shit RBG got for her comments on Trump. From both sides.
There's still an expectation of impartiality. Not every governing body is required or should wade into cross-party politics in an election year.
You're right that the standard FBI response wasnt going to satisfy everyone, but it's not like the response he went with satisfied anyone either. The second Hillary's emails became a partisan issue, there was no longer a response that would have been satisfactory.
My argument is based on the fact that I don't think he was trying to please anyone. I think he was, honest to goodness, just explaining the results of the probe. Saying she was careless is, you know, kind of not 100% wrong? What Powell did was careless. I feel like had he come out and said "This is a disqualifying thing, and she should probably never run for office" then, yes. 100% politics.
It's kind of like when I used to work for an eye doctor. I did something for a patient that wasn't wrong (in that it didn't violate law or policy or anything) but I still shouldn't have done it. The doctor was within her right to say "Hey, that was stupid." She wasn't my boss. She didn't have the right to fire me, but she was responsible for looking into what I did, and it was fine that she did it.
But, yes, no one could be happy with what would come out of the investigation. Period. Full stop. No one. SO, that's why I'm not okay with calling for Comey to be fired.
Well, also because that would be just the dumbest thing possible! The optics (gag) of that would be absolutely terrible.