When I read it I felt it was mostly useless outside of the work sphere. The subtext of it felt like "How to win friends and influence people as a new senior manager or owner of the company" - it dealt with cases where you come in with a lot of power and influence and have to get everyone on your side using your soft skills rather than a big stick.

I agree with you. I have read it, and I think it doesn't help much in terms of "friendship" in general; it is strongly focused on the work sphere.

Ok for casual work acquaintances not for real friends