I agree, but he did have options. Why didn't he do it on his blog, then? Or say at the end of a letter: For a more complete response to pinker, see [URL]. We

I agree, but he did have options. Why didn't he do it on his blog, then? Or say at the end of a letter: For a more complete response to pinker, see [URL]. We can conclude that he either had lots of other good arguments but chose to focus on that minor one, or that he didn't have good rebuttals for the other things.