I feel like you might be unfairly judging the book by its cover (or title?). I'd be happy to be proven wrong if you can cite some examples of what you claim. I'd like myself to cite some passages where manipulation is explicitly frowned upon:
> Of course flattery seldom works with discerning people. It is shallow, selfish and insincere. It ought to fail and it usually does.
> Looking at the other person’s point of view and arousing in him an eager want for something is not to be construed as manipulating that person so that he will do something that is only for your benefit and his detriment. Each party should gain from the negotiation.
> The difference between appreciation and flattery? That is simple. One is sincere and the other insincere. One comes from the heart out; the other from the teeth out. One is unselfish; the other selfish. One is universally admired; the other universally condemned.
> If we merely try to impress people and get people interested in us, we will never have many true, sincere friends. Friends, real friends, are not made that way.
> If we are so contemptibly selfish that we can’t radiate a little happiness and pass on a bit of honest appreciation without trying to get something out of the other person in return - if our souls are no bigger than sour crab apples, we shall meet with the failure we so richly deserve.
> So let’s obey the Golden Rule, and give unto others what we would have others give unto us, How? When? Where? The answer is: All the time, everywhere.
> Be honest, Look for areas where you can admit error and
say so. Apologize for your mistakes.
> Promise to think over your opponents’ ideas and study
them carefully. And mean it. Your opponents may be right.
etc.