The original design was based on rewarding and empowering those whose interests are aligned with the long term success of the network. Only being able to vote with vesting stake should motivate people to vote with the long term in mind, and the partial protection from inflation encourages people to vest their stake and think long term also. The vesting period was originally much longer than it is now, which may be part of why we're seeing so much abuse of voting power for short term gains now.

The change to a linear reward curve also decreased the incentive for consensus on upvoting quality content, though the original curve may have been a bit extreme. I think one of the biggest problems is the lack of curation rewards for downvoting. There's a major spam problem and yet we're relying on people to charitably burn their voting power in order to solve it while all the other curators get paid.