I am a a long-term student of consensus process, and anticipated much of the wiki movement. However, the 800 lb gorilla, the English Wikipedia, was naive about consensus process and the community did not realize that it is far from 'quick'. That is, the basic operation of the wiki could indeed be quick, ad hoc, and it was not surprising that this worked as well as it did. However, for the project to be NPOV (express a neutral point of view), genuine consensus process was needed. Outside of narrow circumstances where high consensus is relatively natural, this requires deep discussion and often skilled facilitation.
So Wikipedia failed to be neutral. It has ideals of neutrality, and often meets them, but never became reliable, because of a lack of structure that would make this happen.
As a Wikipedian, first editing in 2005, I eventually came across an abusive blacklisting of a web site that is a library of permitted copies of published on cold fusion, lenr-canr.org. I confronted this entirely on process grounds, my opinion about cold fusion at that time was the standard one: fascinating discovery, announced in 1989, that was unfortunately unconfirmed. I was wrong, very wrong, on that. However, the Wikipedia Arbitration Committee confirmed my complaint, and then I discovered how totally useless this was. They reprimanded the administrator, who then proceeded to retaliate in every way possible, and his friends did, as well.
Wikipedia is vulnerable to factional editing and administration. It is not a violation of policy. It can be difficult to detect, it takes research and objective analysis to do this. And that takes a lot of time, and nobody has the time. If someone does the research -- I did -- the community will assume that someone who is crazy enough to put in that much time and effort *must be* a POV-pusher.
And so it goes. My home wiki is now Wikiversity, where I am active, and where I have been sysop a number of times. Because Wikiversity allows, and allows subpages in mainspace, and implements neutrality inclusively instead of exclusively, there is little content conflict on Wikiversity, and educational resources may be developed there with high depth, while maintaining overall neutrality (if the maintainers of the resource care to make it so, and we know how to do it).