Absolutely makes sense. The dungeon crawler being built from the book is serving a specific purpose. And a bug free game isn’t the primary goal. Of course, it’d be nice, but not the primary goal. I mostly just wanted to point out cases I saw. What code should not go into the book is just as important to consider when you’re trying to teach a point.
Second system syndrome is quite the siren’s song. Making a buggy game has more value than spending all your time building an overly complex system for a game that you might not finish. I tend to still try to make the overly complex system. 