Halliday & Matthiessen (1999: 272):
So the more the extent of grammatical metaphor in a text, the more that text is loaded against the learner, and against anyone who is an outsider to the register in question. It becomes elitist discourse, in which the function of constructing knowledge goes together with the function of restricting access to that knowledge, making it impenetrable to all except those who have the means of admission to the inside, or the select group who are already there.
It is this other potential that grammatical metaphor has, for making meaning that is obscure, arcane and exclusive, that makes it ideal as a mode of discourse for establishing and maintaining status, prestige and hierarchy, and to establish the paternalistic authority of a technocratic elite …