Because most concepts of science, government and the professions are relatively simple, once one understands them, any ambitious scientist, bureaucrat or professional must, in self defence, prevent his colleagues and audience from discovering that his ideas are simple too. All the professional has to do is speak or write obscurely so that no one will really attempt to understand the concepts being presented but will be awed by erudition. The methods of obscurantism are many fold. Ideas are abstracted beyond necessary. Reasoning and sentence structure are convoluted. Facts are distorted. Words are used that are ambiguous or equivocal. Meaningless phrases are inserted in sentences. Words are invented and not explained. Minor points are expanded to the exclusion of major ones. The meaning or consequences of a fact are described in great detail without reference to the reality.
Governmental organizations sometimes develop a language of their own, a diplomatic language, which can be disconcerting to those lacking experience of working with the organization. It restricts genuine understanding of ultimate aims to small groups of initiates and discourages those delegates unfamiliar with the procedures and languages specific to that organization.