Board Thread:Theories and Speculation/@comment-26381547-20150509000749/@comment-17623-20150510001746

the word asspull is overused but there is no denying that the only reason the Tenseigan exists is because Kishimoto needed a way to make a villain any kind of problem without a dojutsu and he killed all the Uchiha. If he hadn't written himself into the corner with all the Uchiha save Sasuke being dead, the villain would have had a Sharingan.

This is obvious in Naruto Gaiden where he clearly gave the fudge up and made the bad guys. Not only is there a mystery boy with the Sharingan, but the other with an Akatsuki cloak?