That's what the Eternal Mangekyou is for. All the powers none of the drawbacks. I'm sure once Sasuke goes blind enough he'll end up taking his brothers eyes.
I thought it was the other way around. Either way, it kind of makes sense for there to have been one guy with Ultimate eyes in the past, and all current eye techniques are just diluted versions of his.
I mean, they also said he was able to use all 5(6) types of Element manipulation. Now adays, being able to mix just two elements is considered a powerful Bloodline Limit.
They already said the Sage created all the Ninjutsu in the world. I wouldn't be surprised if he also had all the Bloodline Limits. And over the generations all of his powers just ended up spread out amongst his descendants. Which could be every ninja in the world for all we know.
I'm not ready to jump to that conclusion yet. Considering how much of the ninja world seems based on lies, it's entirely possible that the person that told us that just didn't know the truth.
Or that Madara is lying now. He is a bad guy after all.