Good point. I have thought of this as well.
There is a review period in current system. During this period, post can only be downvoted. However, for better user experience (people who wants to upvote can upvote), it's only a few minutes now, IMHO it's too short. So I think we can set it longer, for example, one day, so good people have enough time to review and downvote overvalued contents. In regards to the user experience part, it's doable to just let people upvote, and only record the upvote, don't impact the payout value nor voting power.
Actually, the optimal strategy would be to cast a random downvote for every random upvote. That way you'd be pushing more rewards onto the posts that you're voting.
I don't understand this. In my proposal downvotes will reduce total payout of a post. How can you get more rewards by doing so? If you cast a upvote and a same weighted downvote on same post, you won't increase total payout of the post, but will just inflate others' influence, so this strategy would be less profitable than upvoting good contents only.
Yeah, after thinking about it more, I now think I was wrong on that. :) You'd get more for your upvote somewhere else.
My thought was that I'd upvote Post A and downvote Post B to shift some of the rewards from B to A. But since there are many many posts in the world, the downvote wouldn't be an efficient use of voting power.