Because nothing says it does. :/I Mean why not? His rinne Is like no other except for the 3rd eye from Kaguya/Madara. It really should have something to do with why his power is more difined than those before him with the same dojutsu apart from appearance.
Naruto: The Last Moive support your claim because he sliced a meteor in half with just Chidori, but nothing says it was due to have special Rinnegan.