I wouldn't say Tony is like Nash at all. They might produce the same amount of points for their teams, but they do it in a completely different way.
And I think that's exactly what some people (not the trolls) are talking about here. On any given possession, Tony is most likely to dribble up, play pick and roll and score himself. On any given possession, Nash is most likely to dribble around until he can hand an easy bucket to a teammate. They both end up counting for 2 points, as far as that particular possession goes.
Some people will argue that the latter is better than the former, since it gets other people involved and in rhythm. It's truly debatable.
Tony is undeniably an elite point guard, IMO. He has his type of game that gets it done and wins us games. He's not perfect, but neither is any of the other elite point guards (like you said, Nash is actually horrible on defense).