I bought this book despite some of the existing critics, and after reading it, I can see where some of the harsher remarks came from.
I like the format of the book, and the style of the presentation: it reminds me of those "thought of the day" calendars, in a way. Pick a random page, and you will have a nice drawing and a clear and concise text about a variety of subjects.
My interest in architecture stems from level design for 3d games, so some of the advice was irrelevant, but overall there was enough food for thought that I found the book interesting.
I can see how someone who knows architecture would scoff at some of the remarks. Quite a few of the critics riled against the one on "how to draw a line", for instance. But I think these are quite valid. No matter your domain, sometimes, it's good to be reminded of the basics. You'd be surprised how much is taken for granted, as you advance in your skill. And I've no doubt architecture is the same.
But it's true that from the overall feel of the book, it reads as something aimed at the artchitecture student.
However, if there was an equivalent book for programming, I would probably cherish it. Sometimes, it's nice to just think about an aspect of your art and sort of ponder what you really know about it.
Having somebody throw all sorts of subjects at you might make you discover areas you neglected, and send you on your way to research it some more.
Think of it as a nice stepping stone towards a myriad of more specific subjects.
This is what this book certainly does for me, and in this I think it is very useful.