Wikipedia quickly gets political. Even in technical articles, there is an incentive to impose one's own perspective for his field as the "authoritative" version. An important part of contributors, it turns out, are academics working in the field that more often than not are deeply vested in their version.

This is a great system for an encyclopedia that must find the best approximation of the truth, but I wouldn't call it "incentive free". Similar incentives in the social world (pushing out people that don't conform to the moderator's world view) could be disastrous.

Do you have a specific example?

For example, I don't think they used the term "volunteer" in their funding drives. Maybe that's for obvious reasons, but I also don't remember seeing "volunteer" when reading about their approaches to page vandalism, editors abusing power, etc.