I think there might be confusion about terminology. The form of empathy that the author is referring to is more "understanding other people" than being "kind, sympathetic, cooperative, warm and considerate". Basically, putting yourself in the other person's shoes and seeing things from their perspective as opposed to being agreeable or kind. The former is the essence of strategy and manipulation. The latter is generally being a good person.

It's clear that if you want to get ahead in life, understanding how other people perceive things is THE skill. Being warm, kind and sympathetic is also good, but not required. I can understand how being agreeable can be a detriment in many professional situation. The form of "empathy" being described in the blog post is always an advantage.