Board Thread:Naruto Discussions/@comment-5054236-20150717003436/@comment-734582-20151210122848

Lion chakra wrote: I think Naruto has had plenty of trauma. I think it's weird that you'd need to experience trauma again to awaken Rinnegan now. Naruto's been through plenty of trauma, it's not something that happens once and then it's over. Traumas are for life. That's why they're traumas. If Naruto achieved the potential to awaken Rinnegan, his existing trauma would be enough to awaken it immediately.

Sasuke wasn't born with the Sharingan either,

he was born with the potential to awaken Sharingan. Considering the condition, and the realities of life, awakening it is pretty much a guarantee.

UltimaDude wrote: As stated somewhere above, a transmigrant of Asura needs the "eyes" of the Sage (the eyes of a transmigrant of Indra) while a transmigrant of Indra needs the "body" of the Sage (a piece of flesh of a transmigrant of Indra( Yea. It seems that acquiring the chakra of all nine tailed beasts is another way to recreate Hagoromo's chakra. Kurama seems to be an important part in this, as Hagoromo stated that Kurama plus Indra plus Ashura summoned him. It's not entirely clear how, but it may be because Obito stole some of Madaras chakra and gave it to Naruto, granting him the full range of requirements.

Since he doesn't actually possess the Indra path's dojutsu powers, Naruto never awoke Rinnegan.