Why Do Atheists Criticize People's Beliefs?

[Angrboda]

I assume both of us believe there are behaviors that are more or less objectively good and objectively bad.  If that's the case, then whether or not a person is acting according to their beliefs has no bearing on whether or not what they are doing is good or bad.  Do you agree?

No, I don't.  I think that people who act out their religious beliefs in terrible ways are good people who have been compelled to do a bad thing.  The guy who slices up his daughters genitalia thinks he's helping her.  In your thought experiment, that's how it played out.  We had good people doing good things, and bad people doing bad things.  Then, with beleif, a good man doing a bad thing.  An anomalous point of data.  

If the question is what was more heavily weighted, belief or personality...in your thought experiment.......belief, and obviously so.  It was the only instance in which the outcome was not like the others.

If belief can be blamed in person A's case, leaving him blameless, why can't the same be done for C? You're excusing A because you feel his beliefs compelled him. Is C not under the same onus? If we excuse people on account of them forming actions that are consonant with bad beliefs, then there is no one who will not be excused. You've just redrawn the lines so that the person isn't responsible for their beliefs in one case, but they are in another. That's inconsistent.