Later in the submission, Butterick addresses this directly, and doesn't disagree:
> “What do you mean, it’s not a matter of taste? I like using ligatures when I code.” Great! In so many ways, I don’t care what you do in private. Although I predict you will eventually burn yourself on this hot mess, my main concern is typography that faces other human beings. So if you’re preparing your code for others to read—whether on screen or on paper—skip the ligatures.