I don't believe that one account one vote is the best solution here.
We cannot assume that each and every account has the ability to distinguish high-quality content from low.

The introduction of an oracle system as a solution to this seems heavily over-engineered, not to mention seems to embark down a road towards a distributed identity verification, AML/KYC.

If my understanding is correct then, in my opinion, this would be a gross misallocation of resources by Steemit, Inc and at best should be outsourced.

I would favour a more meritocratic system.
What I would propose is to completely disable the Power Up feature at the smart contract level.
User's steem power would only have one single source and that's through reward payouts.
I would really appreciate some thoughts or criticisms on that approach!