Most self-help advice about interacting with people is pointing out ways that get some desired interaction effect. They may be true in that they are pointing out those real characteristics which lead to those effects, the result of putting them in a book and studying them makes the reader a student of manipulation. Depending on the student and the target of the trained interaction, it may work as intended or it may label the student as a manipulator to the target.
In less abstract terms, it is not hard to learn the “tricks” and notice when people are using them on you, and it becomes incredibly irritating being around people who interact with you on that level.
Basically, if you’re interacting with people because you were told to do it that way, it’s probably manipulation. Teaching people to be empathetic and interested isn’t very easy and the more popular methods of faking it are pretty transparent.