Think back to how he handled the Miller/Blake thing ... not exactly what you look for in a leader.
leadership is sort of an intangible thing. Kind of like describing the difference between artistic nudes and pornography -- I can't describe what exactly makes them different, but I know it when I see it.
For instance, I think there's really only one guy currently under contract that has the charisma, demeanor and affect of a leader: Wesley ... unfortunately his talent level doesn't back it up. On a related note, I thought Lillard came pretty strong in some of the interviews I saw with him. Hopefully that's real and not just the product of studying with a media coach.