I believe the essential characteristics of leadership blend specific knowledge and analytical skill, genuine communication, a willingness to consider possibilities, and the courage to decide and act.
In both my major corporate experiences and almost two decades of small business ownership, I too often failed to acknowledge the 90% positive level of employee performance, mentioning instead the 10% we might have done better. The need to affirm and genuinely express both achievement and opportunity for improvement among employees was certainly well taught in Harvard Business School classes. A better adherence to those lessons would have made me a better leader.