I pointed out in another thread that Naruto may need to learn to communicate freely & establish some type of relationship with the fox in order to use its true power.
However that may not be the only reason too do so beacuse I think the Fox may also know secrets about Madara. At the very least it knows about the incident 15 years ago in Konha.
What I'm wondering about is twofold :
-1st Is Naruto the first host of the 9 tailed Fox or was there someone before him from the land of fire?
It is possible that after the 1st Hokage defeated Madara he took the Fox and sealed in a container or in someone else for safe keeping.
- 2nd In the connection between the Uchiha Clan and the Fox it states that the MS has the power to control the 9 tailed fox but it doesnt say other tailed beast just the fox.
I suppose if it could control other beasts Sasuke could have used it on the 8 tails.
My Best idea is that this is related to the fact that the 9 tailed Fox is supposed to be Fire elemental based and the Uchiha as we know have a strong affinaty for Fire.