I think any belief in the wisdom of the crowd is a fallacious assumption. People lack the virtues needed for just self-policing which is why rights such as freedom of speech must be coded into law and enforced with violence in the real world. Encouraging downvoting will open new avenues of self-righteous mob-mentality witch hunts where gangs will begin voting against those with whom they disagree or those who have downvoted them instead of honorably curating rewards.
I've noticed that the changes proposed by Steemit almost always favor the largest wallets and that's no surprise considering their stake, however I do appreciate the recent attempts towards open and honest communication on the blockchain.