I'd argue that your objection smacks of American exceptionalism. Or at least some strange form of American snobbery. Would you make the same case if I'd used some analogy from African history? Or the Middle East? Or Europe? I don't think so. But because this is from America's history it's somehow insulting to use it?

I didn't use the example because it's American history, I don't consider American history to be special. It's simply history. Human history. And a history I'm familiar enough with to write accurately about. As I said, the analogy sprang to mind almost as soon as I hear about the attack and saw people complaining that Palestinians didn't all condemn Hamas. Because it was a useful way of understanding how oppressed people would fail to condemn an act that was objectively awful.