Naruto didn't reach full potential, only when befriending Kurama that he seemed to be able to manipulate its chakra to the max (Allow others to use it for instance). I believe the temple was a way for Jinch to master the Bijuu's power without giving it the freedom Bee gave to Gyuuki. 
Though I guess the special temple would allow an easier access to hax abilities, I think it would probably be more interesting to have the two develop and have GM's watch over the development.