Katz started the research focus on skills during a time when there finally was a definitive list of leader traits described in the literature there was no research yet on the individual attributes of leaders there was emphasis in the literature on putting followers first there was still disagreement about leader traits in the literature

I believe the answer is There was still disagreement about leader traits in the literature

For example, in the past, researchers fail to attribute physical traits such as, Facial feature, height, and weight to effective leadership. Recent science shows that good physical traits tend to attract attention from others and give more commanding presence that could make someone's percieved as an effective leader.