Their argument is demonstrative rather than persuasive (although there is a persuasive component, but they expect interlocutors to be familiar with structuralist theory, which is not unreasonable in an academic setting). I'm not sure this is the most effective way to communicate their ideas, but the frustration and discomfort they are causing to other people is something that they have a lifetime's experience of, which is why they are able to push people's button's so effectively. They are showing people what it feels like to be unexpectedly and unjustly placed into an out-group.