If you wanted to make your comment useful to other readers, describing the argument you would reach for would be a good step. I read the same section and though

If you wanted to make your comment useful to other readers, describing the argument you would reach for would be a good step. I read the same section and thought it was a reasonable response to an objection I have seen come up (slightly different context---it wasn't HtDP but still a change to the introductory programming course.)