This defensiveness is a natural human reaction to perceived attack. It is much easier to do than to try to understand the underlying issues involved. Heck, most people can't understand their spouse, let alone someone who is different culturally from themselves. I see it as an expression of frustration that stems from conflicting messages. I've seen it up close and personal from both sides. There is an attack from some folks in our society on the white middle class, and there is an overreaction from some of the white middle class in response to it. Most people are caught in the middle, your average white middle class male wants to be fair to folks, but doesn't know what that means and gets accused of things they aren't, and your average non-white just wants the same opportunities and to be treated fairly by the system. And on the extreme on both sides are a whole bunch of people yelling back and forth. And those in the middle will be accused by both sides of being traitors or abusers or whatever. Which is true of just about every human conflict.
You're right, and this is a good summary, I just like having fun with it.