Thanks @stoodkev for reminding everyone that there's a difference between wishing Steem would change in some way and having a technical proposal that could actually push the network in that direction. It turns out to be extremely challenging to engineer incentives without unintended consequences. And in a free market where upvotes have value, I don't see how you could successfully regulate vote selling.

Curation rewards are somewhat of a regulator... you have more incentive to vote for good content that others will subsequently upvote than bad content. But push the pendulum too far in this direction and people will start only voting based on what others like.