This is late, but it's because of his Eight Trigrams Seal. Only Naruto and Minato had the Eight Trigrams, because it was a special seal created and used by the Uzumaki clan primarily for such a purpose, Kushina use her Adamantine Chains, so she never needed it. Also, only Minato and Naruto could manifest their forms as pure chakra.
Given to Naruto at birth, the Eight Trigrams seal slowly leaks Tailed-Beast chakra to the Jinchuuriki, the longer two chakra flows are in contact, the more in sync they become. Naruto and Kurama are considered perfect sync by the start of the Fourth War, the only thing that held them back was their personal feelings and cooperation. Other Jinchuurikis were either in control (i.e. Bee) or taken over by their Tailed-Beast will (i.e. Gaara). Only Naruto and Kurama had everything set up to be a perfect Jinchuuriki/Tailed Beast relationship.