To a certain extent, DU is still an experiment as a forum using juries in this way - I'm unaware of another forum doing the same thing. And some people will find that they prefer a system with a few moderators with the powers to control the insults, instead.
But there are problems with moderators, especially on a large site. There's a lot of work to do as a moderator; I did it on DU, for perhaps 2 years in all, and found I couldn't post much, or even read much of DU that wasn't related to mod jobs, because there's always another alert waiting to be dealt with. If you try to deal with this by splitting up the forum into areas, and telling moderators they only need deal with one area, which their small group of mods has the responsibility for, you can still end up with inconsistency in the decisions - and then it would be an inconsistency that would continue for a long time. If you have a lot of mods, but say they can roam over a large area, you'll end up with a few awkward mods who slow the whole process down by always saying "no, we need to talk about this more before deciding".
The idea of the juries is that you'll get a fast decision, but you're not stuck with the same group deciding things time and time again. When dislike of moderators' decisions builds up, and gets expressed on the forum, it rapidly puts moderators off volunteering their time to the board. People don't appreciate being called 'fascists' when they're putting in more effort to run the community than their critics. I understand this was a significant problem towards the end of DU2.
DU was founded basically as a protest about the way Bush was installed in 2001, when the Supreme Court seemed to say "we've got to be decorous about this - a recount could cause bad feeling, so we won't try it". So DU has always attracted those who are vocal about their beliefs. And we've always been free with the insults of those we oppose - eg Bush. When a significant difference in opinion appears within Democratic ranks - eg during the presidential primaries of 2004 and 2008, over whether Pelosi should have impeached Bush in 2007, over the bank bailout, or now for drones and the NSA, you get fights. I suspect more people got banned under the old moderator system - possibly because that's necessary to keep the moderator workload down (the 'frequent fliers' in mod discussions were infuriating). Now that the workload is spread over most of the community, that's not so necessary.
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