That you've said nothing about those topics doesn't mean they're irrelevant. They operate on the same principles you're basing your argument for the legitimacy of this practice on. If you're reluctant to address how the principle applies as a point of comparison for why it might be unjust, maybe you should re-examine the principle. If you're concerned that doing so might make you uncomfortable, then you should definitely re-examine the principle.
You are mistaken. It's not that I'm not considering those topics. It's that I'm refusing to allow you to lead me around by the nose and make me chase after whatever point you want me to address, derailing the original conversation.
So you would regard this argument as likewise applicable to whites-only events, right?
As that's an entirely different situation, with an entirely different context, seems pretty easy to say I'd feel differently about it.