Should take findings with grain of salt.
I asked Rudder at a conference if he normalized the results, he said he did not on that blog post. Didn't account for education level, kids, etc. Which may (or may not) had an effect on the results.
As for education and kids, I can see how that can explain the difference between Asian women and Black women's response rate. But again, need a real examination of the data.
It is a very touchy subject, which is unfortunately plagued by both uninformed people and also those who just want to cause pain to to others.