Jaejoong was the oldest, so he was suppose to be the leader. But he thought it would be to much. So he reclined. And then Yunho was the Далее oldest, so he was Далее in line to be the leader. Of course, he accepted.
Because he is caring and kind. he takes care of all members. all of them include Jae regard him as the best leader. they had сказал(-а) that without Yunho, there's no DBSK. in my viewpoint, he is not only charisma but also kute. he is a real leader.
at first,this place was дана to jae joong but he did not want to do a leader and neither the other members.but when it is дана to yunho,he accept it. thats all!!
because when SM ask jaejoong and other members to be the leader, he didn't accept it,but when SM ask yunho,he accepted it.so now he become the leader.and i think yunho is a good leader :)