Well the thing is, it's not really "voting." You're actually sharing. When you share a post, it brings it to light on the feed of any person that is following you. That way, people of like minds and like passions can discover things together. So it's not really re-posting per se, but spreading the word.
Yes, and AFAIK, sharing-on-your-feed is exactly what Tumblr's system is, and that hasn't exactly turned out to be a bastion of... anything, really. If Hubski seems good so far, it seems more likely because of the community than any underlying system. I like the community, but things like the prevention of insular groups(and the resulting brigading) is legitimately hard... How is hubski's system equipped to handle these problems? (Edit: just to be clear, I don't intend this to be snarky, I'm legitimately curious about this problem. Reading through the primer now.)
I think it's mostly a function of the looseness of the "groups" of Hubski. Since there aren't subreddits, posts get grouped by poster/sharer, tags, and badged. Basically instead of walling off groups from one another Hubski lets each person define their own content groupings. You're sort of your own mod on Hubski, deciding what and who you want to see more or less of. Things that most people don't care for can/will be filtered and trolls/spambots just end up talking to each other, if anyone. Even though you don't necessarily see the same posts as everyone else Hubski gives more of a feeling of a singular community rather than many fragmented ones IMO.