This is similar to what I have observed. Maybe the steemit button could mean "bookmark to steem". Voting up or down is too easy, but bookmarking or sharing indicates some actual value, and as such could be given greater voting power.
If the subject is negative like some disgusting news, it might still be valuable. This makes voting hard because you associate upvote with like. Maybe an algorithm that identifies controversial posts and boosts their total votes if the sum is positive. A controversial conversation might be valuable. I don't know..