In 10:30 the people had asked Yisro to stay with them but Yisro responds that he will not stay but he will go back home to his land and to his birthplace.
Yisro's response stands, in my mind, in stark contrast to the response of Avraham who was also implored (albeit by God Himself in that case) to leave his family, his birthplace and his land to go to the Land of Israel.
Avraham, as we know, did so because he had found the truth and knew he had to follow it.
Yisro found the truth as well, but he could not give up his personal needs and preferences to follow it. When push came to shove, despite his being so great, and even the father of the Jewish Judicial System, he could not take that step to throw his lot in with that if the jewish People. He could not give up everything to follow and be a part of the truth.
This shows that mo matter how great a person might be, everybody still has negios. They have preferences with internal conflicts that are often difficult to overcome. When they do overcome them, it shows how great that person and his dedication really is.