Board Thread:Naruto Discussions/@comment-24120130-20140607191120/@comment-3568954-20140702024727

Mrlmm0605 wrote: It is totally impossible for Hagoromo to have a kekkei genkai not possessed by Kaguya. The laws of heredity, which Kishi tries really hard to abide by, deny even the possibility. Therefore, Kaguya had to have a Rinnegan. It can, though, be a subtly genetically different Rinnegan than that of Hagoromo, because of the recombination of genes. In a story context, all chakra abilities had to have originated from Kaguya, because al chakra originated from Kaguya. There is no middle ground. Either Kaguya has the Rinnegan, or there is no such thing as a Rinnegan. One of those is obviously false, so we have but one option.

By your logic she must have every Dojutsu

she must have Ranmaru's dojutsu

she must have Deidara's dojutsu(he created that himself)

is it so hard to believe that maybe just maybe Hagoromo was not born with the Rinnegan maybe just maybe he was born with a Sharingan and simply trained it and evolved it the same way Deidara trained his eye to be immune to genjutsu