Abuse and harassment on Wikipedia does not belong to a handful of editors, it's endemic, because the only way to succeed on Wikipedia is to be an asshole. But it's important to note that bad behaviour on Wikipedia is a symptom of poor software design. The software that Wikipedia is built encourages conflict, and uses hundreds of rules combined with poorly-trained admins to try to patch things up. The boundaries between conflict and abuse are wide, arbitrarily defined, and patrolled by people who have neither training, nor consistency. A better designed system would install systems to minimize conflict, and would give clearer rules and standards to it's moderators.