Personally I read the book years ago and found many pieces of actionable advice. For example after years of having very distinct friend groups, I started mixing them together and the result was great. Tons of small tips like that.

Yes you're right, this book isn't for a serious introvert. But Keith never claims it is? Writing a book for everyone leaves you with a book that's useful to no one.

If I write a book about compilers, maybe even mention my book will make someone a better programmer, I don't expect the frontend guys to complain it's not accessible to them. I honestly struggle to understand where this mindset comes from.