Offline, we have to deal with caged monkeys throwing feces all the time. From political organizations of all ideologies to middle management, groups of people get angry or power-hungry or self-righteous and do things they shouldn't. Sometimes it is someone in power like police officer or a doctor, other times it is a group of teenagers who are just hellbent on stirring things up. But regardless, it is a fact of life that troublemakers exist in numbers and screw things up. We don't always win against those who we perceive as jerks in the wrong, but we don't expect to.
People talk about their experiences with Wikipedia and treat it as if it were somehow different from every other institution on the planet. They expect some utopian harmony where people are calmly and coolly working together for a common goal. And most of the time, it is like that. Yet like everything else, it isn't perfect, people break rules, there are jerks, bad things happen to good people, and so on. What gets me is that for some reason, people just give up on Wikipedia when they would normally defend any their involvement in other civic, non-profit, for-profit, governmental, or educational organization.