Well, the main problem there is that those kinds of people are often accompanied by other people who agree with them and do appreciate their poisonous methods as "spreading the truth at any cost". It's possible that those people will end up forming their own "network" following each other, and then the same political tensions that make Reddit and Twitter toxic places will destroy Hubski as well.It will be interesting when we get some people who deliberately try to game the system and see how they dance around trying to inject their poisonous methods of discussion into threads. My feeling is that the self moderating functionality will do a good job.
There's a certain danger in self-curation where you walk the line between following those who present you with new and interesting things, and creating a walled garden where you don't have to listen to anyone you disagree with. For now, my first impression of this site is that most people are here for the former, rather than the latter. But just in the way reddiquette went by the wayside in favor of a "like/dislike" model, I'll be curious to see what a larger userbase might eventually change things.