That's like saying being a mathematician involves how well you can sell yourself, therefore marketing and networking are core skills in math. Marketing and networking are core skills of life no matter where you are.
Nope, as the OP said, you are misunderstanding that these books aren't teaching "soft skills", they aren't about networking or marketing, they are about how you collaborate in a work environment and build maintainable software that meets deadlines. If you haven't give some of them a shot, I find them a refreshing break from algorithms heavy books and get a lot of value from them.
