Right, from time to time I see threads discussing Vol'jin, yet each one starts off with discussing why posters either dislike him or think why he will be a bad warchief.
I want you to keep in mind what has been written about him in the books, short stories and of course ingame amd find reasons why he will be a GOOD warchief.
And please, discussing Garrosh, Thrall or the Old Horde is not needed here, I've already read those opinions before.
I'll get you started off with saying that Vol'jin is a very intelligent leader who has taken a very small tribe of trolls to a position of power far beyond what they could have hoped for when they came to the Echo Isles.