You’re over thinking. I wasn’t offended. I was amused.
Whatever emotion you call it, it is obvious you disagreed, and tried humor to mock his view while mis-characterizing it. While I wasn't going to rake you over the coals for your misstatement, you just invited it. So you should say ouch a few times and perhaps we could move on.
On a naturalist view, how should nazism et al actually offend us?
My contention is that naturalism gives no support of the notion of "should" in that sentence.