It reasonable to "boot" somebody from the organization, provided it is done in a fair, evenhanded way. But WT disfellowshipping goes far beyond mere removal. It includes encouraging members to cause emotional pain to those in the organization's bad graces, and effectively slandering them with a public announcement at a meeting where the accused is likely to be present. The literal wording of the announcement is innocuous ("Tirebiter is no longer one of Jehovah's Witnesses"--not that I ever was!). But the sinister connotation those words have to those hearing them ("Apostate! Fornicator! Bad Association!") conveys a different meaning--a case of loaded language.
The WT policy on disfellowshipping has not always been so extreme. Aussie Oz has documented the history of how this policy has changed through the years, which you can read at freeminds.