It's just your tone about the whole thing. While I disagree that what she said is bigoted, let's assume for the sake of it that it is. What useful purpose does it serve to point out that, in the heat of the moment, someone said something bigoted, outside of scoring points on the Internet?

I mostly took issue with the phrase "The chain of ignorance must stop." it makes it sound as if, of all places, you're taking a stand right here and saying that this person right now needs to be corrected. It seems tasteless and misplaced.

I would point out that she seems to be attempting to say something along the lines of "I don't know what god these people believe in, but none of the gods I know of would approve of this", which is a pretty believable reaction to a horrible event by a religious person, not "Only godless people would do this.". The other reason you come across (to me) as a bit crass is because you appear to be looking for a slight against atheism where there isn't one.