Fair enough, but if that reasoning stops any white racists from trying to correct their own ways, then it's not even worth mentioning. Childish as it sounds, the whole "but he started it" argument is used by enough adults to cause the breakdown of peacemaking worldwide. See also, Israel/Palestine. If a person, white or otherwise, realizes his own negative tendencies but then refuses to change on the grounds of "why should I? Those people do it, too," that's called being petty.
No hard feelings. When ever anybody disagrees with me about anything, I always assume first that they were somehow distracted or under duress.