Really it comes down to the fact you can earn 4x the amount of Steem then any other method. Regardless of what the point of Steem is, if we want to see the currency used to find great content, what PoB was invented for, then we need to somehow reduce the gap between selling votes and curating. It's really that simple, most people will continue to sell votes or self upvote (even if they dont want to create content, some will put out a few lines just to selfupvote because its the best ROI) - Ecosystems run on incentives, if you make one thing lopsided, it strangles the rest of the system.