Board Thread:Fourth Databook/@comment-24577388-20141105025614/@comment-4912646-20141105062540

If we assume Naruto would have qualified as a Wind Release user as soon as he properly created wind chakra for the first time (splitting a leaf in two), then just having a nature doesn't really mean much at all. That only took the average ninja a few months of training, according to Kakashi. Let's also not forget that Sasuke learned Lightning Release and an A-ranked technique of said nature in only a month. So why is having all five natures even a rare thing in the first place?