My personal hypothesis is that much wikipedia incivility is part of the broader internet-troll phenomenon (google "Don't Read The Comments" if you're unfamiliar with the effects of trolling). I'd be very interested to see a linguistic comparison between classes of edits/comments tagged as 'bad' across a range of sites which allow unmoderated comments.
Being able to confirm that large part of the problem was actually part of an internet-wide problem rather than a local problem would be a big step forward.
It worries me that the WMF may, by making the wikipedia interface more similar to other discussion systems, reduce the differences between us and the troll-infested platforms and make it psychologically easier for those who troll on other platforms to troll on wikipedia.
cheers stuart