While I'm sorry you didn't find the book that useful, as with all books, I highly recommend checking out the preface before buying (you can use Amazon's "look inside" feature) to determine if this book is right for you.
We point out in the preface that it's a principles and practices book that covers a broad range of topics and how they fit together, rather than a book that dives into a lot of implementation details, which it sounds like you were expecting. Having said that, I believe we cover things in quite a lot more detail than your bullets suggest.
We also point out that you shouldn't necessarily read it cover to cover, that it was designed such that you could dip in at the relevant bits for you, and that designing the book this way involved a certain amount of repetition.
If you're very experienced and technical, I'm not surprised you found the first few chapters dull and repetitive - they were the most high level, targeted at people new to the topic. That's why part 1 (chapters 1-4) is called "Foundations". Probably you would have been more interested in the later, more technical chapters - chapters 5 onwards, and for advanced practitioners, chapters 11 onwards.
I definitely wouldn't say we were only targeting managers - we only get one shot at the book, and we've tried to include both material that is suitable for management and for technical people, and to make clear what should be read for each target audience. In our experience, management and technical people need to work together in order to achieve the vision we set out in the book. Part of the goal of the book was to arm technical people with useful arguments to be able to take to their management to get buy-in to implement these ideas.
Perhaps you're right that the material relevant to you personally could have been written in 150 pages - but unfortunately that's the problem with writing a book - it's impossible to customize it meaningfully, especially in a book like this which targets a broad audience and covers a broad range of material.