Board Thread:Wiki Discussions/@comment-3238846-20140422105553/@comment-1512913-20140422135825

It isn't, it's a completely valid reasoning. Chapter 674 has made it even more obvious that Naruto isn't the user of the natures, he doesn't even know what to do and had to have had Shukaku tell him. Naruto hasn't magically learned Katon and Doton from nowhere (because duh, natures have to be learned and they don't just appear) nor has he learned whatever natures make Jinton up. There wasn't a time for that, he was half-dead if you didn't notice.