Being pleasant is one of my personal rules/goals for life.
But it is interesting to analyze great leaders who have been jerks. This 30 minute Youtube documentary on the topic is very interesting: "DICKS: Do you need to be one to be a successful leader?" https://youtu.be/gRRvjZ_XNog
In bigger projectd and groups people need structure. If you're goal is provide success and structure for the people involved you can't let other people's lack of structure hurt everyone else. I think the "Kind of a Dick" is more of a cultural shock issue. You can be pleasant, but also blunt and honest about what needs to be done.
But it is interesting to analyze great leaders who have been jerks. This 30 minute Youtube documentary on the topic is very interesting: "DICKS: Do you need to be one to be a successful leader?" https://youtu.be/gRRvjZ_XNog