He was one of those people "I should get the absolute maximum I could ever get out of any situation." He did get a better offer, and so he was successful in that. He also created much higher expectation of what he could do "he really negotiates hard, I hope he is worth it" kind of vibe.
Fortunately for me, I went in creating reasonably modest expectation (let's say I don't stand out) and I was able to vastly exceed those expectation while he came with inflated expectations that he fell short. Not a great way to start a career. And it went downhill from there for him.
People do make judgments about another person based on factors like this. In my friend's case, I wasn't the one judging him as a tough negotiator (I was a nobody), it was the manager who hired him.
My point is: articles like this should not be taken as the gospel and my own advice is not gospel either. Evaluate your particular recruitment situation (as a job seeker or as a recruiting manager) and act with judgement and common sense.