[HankStallone]

Often the moderator is the project lead (or one of them), who may not be suited to adjudicating personal disputes and probably has better things to do. That can result in siding with the louder faction in the hopes that giving them what they want will satisfy them and let everyone get back to work. Or worse, turning the job of moderation over to them because they seem to want it, and then the petty tyranny is off to the races.

I think that happens less now that people are aware of the danger; but a decade or so ago it was a real problem because no one saw it coming.