We all have in mind the image of a shouting boss or an ever complaining manager blaming others rather than themselves. If you have anything to ask them, be it a pay rise, a holiday, you'd better forget about it or find another way... if not another job.
On the contrary a good leader is sensitive and shows empathy. It's not a weakness but a strength to be able to listen to others rather than tell all the time. It's important to know where you're going and keep to it, but along the way there will be trouble and chances are you'll have to steer the project into another direction.
That's why leaders who know themselves have a great advantage: deeply knowing what's best for them, the project and their team, they rally people to do their best.