* mean and incompetent people sometimes are found to be High Conflict Personalities, as defined here:
http://www.highconflictinstitute.com/index.php?option=com_content&view=article&id=38&Itemid=101

*In Information Technology, they can also be defined as Paranoid, Incompetent Micro-Managers (PIMMs): http://www.softpanorama.org/Social/Toxic_managers/Micromanagers/fighting_micromanagers.shtml

* These types of "mean/incompetent" people may also have "Cluster B" Personality Disorders (Narcisstic, Histrionic, or Borderline) as defined by the APA's DSM-IV-TR: http://en.wikipedia.org/wiki/Personality_disorder . Some may engage in distortion campaigns as a way to hold their jobs, or for other purposes: http://angiemedia.com/2008/12/29/bpd-distortion-campaigns

* Such people may also exhibit Passive Aggressive or Covertly Aggressive behavior:
http://www.positive-way.com/business/passive_aggressive.htm
http://www.personal-growth-programs.com/index.php/sample-pattern-descriptions/73
http://www.manipulative-people.com/the-covert-aggressive-personality/
http://www.familylawwebguide.com.au/forum/pg/topicview/misc/1129/index.php&start=0&keep_session=69535104#post_5195