Yes, you’re totally right, creativity is absent from this book, exactly like in GTD, although the chapter 6, The Elements of Decision teach you to focus on the overall structure instead of the problems, so it can lead to creativity.

But in general theses books teach you to be effective in your today world, not to think and create what you want. But others books, like The Path of Least Resistance or The Creative Habit do the job really well

And I didn’t read others books from Drucker, so I don’t know if he talk about that elsewhere.

Being efficient refers to what we already know and do.

In Drucker’s vision it is not the excecutive’s job to open a new market. He probably thinks this is the job of another department. Unfortunately it often isn’t – which sometimes leads to unfortunate consequences.