David Graeber is sort of the Jamie Oliver of anarchism: he demystifies the ideas and practices of modern activism and explains complex issues in a non academic language.
What makes him stand out as a left wing political thinker is also his actual experience of practical political organising, from the globalisation movement and Occupy Wall Street. That puts him in a special line of writers, like when Che writes about guerrilla warfare or Lenin about the state and the revolution. You don’t have to agree with these people to find their point of view relevant for discussion.
Unfortunately, this is also something that alienates him from “mainstream” Marxism. Most people in these circles base their ideas about organisation on the structure of the labour movement a hundred years ago. But lets face it, the organisational structure of the dominant protest movements of the last thirty years has been completely dominated by anarchist and feminist ideas.