Comment by jghn
9 months ago
Because the pendulum of typing hadn't swung back to static being in vogue when the Philosophy of Software Design came out. At the time you had mostly the Scala & Haskell people standing in a corner screaming until they (well, we as I was one of them) were blue in the face about reducing "certain types of bugs", and making impossible states impossible.
Since then, everyone and their brother is on the static typing train. And from that lens you're right. It seems like an omission. Give it another 10 years and people will probably think the opposite.