Why can't you engineer away jerks? I mean, we have democracy, free markets etc. and among their main contributions is to engineer away the effects of bad behavior. In a democracy, you won't get the best decision, but you will get an acceptable decision. In a free market competitors force business to serve the customer.
Similarly, a techical solution which gives jerks a smaller influence seems an excellent partial solution. Sure, you might still need policing, but it isn't either or.
Even if it were true (and I really don't think the majority is the problem), the whole point of the proposed system is that while everyone can sign up, only quality posters and commenters will progress to have any influence over the site.
Similarly, a techical solution which gives jerks a smaller influence seems an excellent partial solution. Sure, you might still need policing, but it isn't either or.