This is old news in a way – a talk on Wikipedia given in 2009 by an academic who specialises in online studies. However, I couldn't find any previous discussion of it here. It's a very clueful analysis. Video of the talk
, related webpage
, plus some slides from a talk by Jimbo
she refers to.
The greatest threat to Wikipedia is its community. ... The community is very off-putting to occasional contributors. ... It's scary, it's aggressive, it's often ignorant.
(Posted by someone on the Gendergap list.)